Edit: Updated March 2022
Hey, I'd like to share my experience in Dorfromantik and tell you how I finally broke the 100k points threshold! Initially, my highest scores would be around 20k. I really tried to get more, and a couple of times I managed to get past 30k. My absolute highest was 43k.

However, I saw people reaching 100k, 200k, even 500k! I didn't think this was even possible, but all those people couldn't be cheaters, so there had to be a way. I started researching strategies for achieving higher scores. Nobody seemed to have a simple answer, but by combining bits and pieces of information from multiple sources, I finally came up with a strategy that seemed promising. I put it to the test, and immediately it worked like magic! That game I made it to 270k! Currently, I'm playing a game where I made it to 325k so far, and I have well over 100 tiles left.

So how do I do it, you wonder? I'll tell you in 7 simple steps!

This seems obvious, but it has to be mentioned: in the beginning of your game, your focus will be on quests, since early quests are finished quickly. But with time, quest requirements grow. So quests alone will not sustain you. This is why most people don't get past 20k or 30k points. They focus on quests almost exclusively, and eventually and inevitably they run out of tiles on the way.

If you're a player looking to boost your highscore, you probably already know this: surrounding a tile with six other tiles in such a way that you match all biomes on each side perfectly will reward an extra tile for your stack. By that I mean match meadow with meadow, forest with forest, wheat field with wheat field, house with house, and so on. So potentially, you can get seven extra tiles by placing just one tile, assuming everything on all tiles fits perfectly.

As quest requirements increase, perfect tiles will keep you afloat in between finishing quests. Eventually, finishing quests will become something you do “accidentally” while looking for perfect tiles.

When you finish a triangle quest and a flag appears in the town, forest, or field you've been working on, the extra quest is for you to close off all openings for an additional bonus. Usually, this is not very rewarding compared to the extra effort you have to put in.

My advice is to grow a large field or forest or town and eventually have multiple flags in it before you close it, if you choose to do so. I'm talking at least five, better eight or ten! This could be something you set up and then do as life insurance should you ever start to run low on tiles! I once closed a forest with multiple quest flags and got 56 tiles for that!

However, there is a hidden advantage when it comes to closing quests: this also resets your quest requirements! Most people don't seem to know this. I didn't for the longest time! One of the reasons why many players don't want to close off a huge forest, for example, is that their forest quests have risen to astronomical numbers, and they think if they close it off, they will never be able to finish another forest quest again, since they would have to regrow another huge forest first! This is wrong! When quests are generated, the game looks at your largest forest that is still open, and adds a few trees on top of it for the quest requirement. This is why closing a large forest at the right time can make all the difference!

Also, if you are about to uncover a bonus quest, and from the shape of the preview you already know it's gonna be a forest quest, for example, and you have a huge forest about to close, consider to not unveil the bonus quest until after you have closed your large forest. That way, the bonus quest will have a much lower requirement.

Most people don't seem to know, and in the beginning I had no idea myself, but there is no penalty for failing a quest. The game generates more quests for you if you don't have a lot of open ones. It doesn't care if you botched a quest or finished one, if a quest is over, you will soon be presented with a new one. This means you should be somewhat picky when it comes to the quests to choose. If a quest is an inconvenience, if it's not worth your time, fail it and wait for a better one to come along!
Bonus quests you uncover along the way do not count as open quests, by the way, and neither do flags.

I've mentioned sacrificing quests, but now we have to talk about sacrificing perfect tiles. I've only recently noticed this, but for the longest time, what held me back in achieving higher scores was my OCD-induced ridiculous level of perfectionism. I couldn't bare to place a tile if it meant five sides were perfect, but the sixth side wasn't. I would rather wait for the perfect tile, even if it meant it never came and instead I ran out and lost the game.

It is important to strike a balance between playing perfectly and cutting your losses if you need to. You cannot let perfection be the enemy of progress! I've learned this the hard way, but it is better to accept small flaws to achieve the greater goal. Five, four, even three perfects instead of six may not sound appealing to some, but especially in a pinch, this is totally fine. It's certainly better than none!

Especially as the map grows larger and larger, it is sometimes necessary to scroll the entire length from north to south and from east to west in order to find the perfect place for your current tile. Sometimes you even have to do that twice! When I look for tile placements, if I find a good spot, I don't place it immediately. I keep looking and only if there are no better spots I return to the previous place and use my tile. Remember that there is no time limit or penalty, even if you take several minutes for a decision!

I noticed I would subconsciously make decisions faster and more frenzied the closer I got to running out of tiles. Of course, you should do the exact opposite, taking more time the fewer tiles you have, to make sure you're maximizing your chances!
A good memory also helps in finding the best spots, but it's no substitute for checking and double-checking!

With time you will inevitably learn which tiles are helpful and which aren't. Generally speaking, any tile with lots of meadow is a good tile, but any tile that features three different biomes and only one or no meadow isn't very helpful. It'll also be much easier to remember that (and where) you need a tile with 5 sides meadow and one side wheat field, for example, than to remember where you have to place a tile with a house, a field, two trees, another house, and another field.

You should try and build your world accordingly. Since you know that perfect tiles are the key to a long game, try and purposefully build holes in your map that you can easily fill. For example, have an empty spot where all the surrounding tiles have meadow borders. That's an easy perfect tile!

As well, don't place tiles that would leave holes with difficult biome combinations! Leave these spots open until you get a problematic tile. For example, you have a hole that is surrounded by four placed tiles already, and you need two houses and a field. Don't put more tiles around this hole, wait to fill in the hole first. Otherwise you may need two houses, a field, and two trees, for example, and that is going to be very difficult to get (and to remember)!

Another area of difficulty: train tracks and rivers. These are complicated tiles, because they seriously limit your options by default. Most people intuitively know that, so they build train tracks and rivers away from their main map in a straight line. That's not a good idea though, because this way you'll never get any perfect placements and will eventually run out of tiles.

A better way to deal with this problem is to try and have your train tracks and rivers run parallel to the borders of your map, with one or two empty spots in between, and then fill up these empty spots whenever you have the chance. Make sure to not run across where you are growing a huge forest or town or wheat field though! Simply let your train tracks or rivers circle around and go back the way they came, again with one or two empty spots in between if necessary. It is also advisable to always have multiple train track and river openings (on the same train track or river or on multiple ones) in order to have options!
Your map should always be somewhat round. If there are gaps, you should strive to fill them!

Oh, bonus tip: water stations can be connected to rivers as well as train tracks! Use those wisely! Plus, water (as in lakes/water stations) will perfectly fit to more water, but also meadows!

Lastly, remember to take breaks! Rome wasn't built in a day. Your masterpiece shouldn't be either. The longer your session lasts, the more you'll make mistakes due to lack of concentration. Leave the game be and do something else for a while, then come back to it later. It'll still be there.

I hope I was able to help you with these tips, and good luck getting to 100k points and beyond! Let me know if you did! Oh, and I have a Dorfromantik Facebook group you can join to share highscores and screenshots!
https://www.facebook.com/groups/2432751230192082