How to make this game easier and feel less repetitive.
1. Check what you need to achieve on the top left to unlock as many crowns as possible in every run.
2. When unlocking tech trees, do not branch out, go straight up. Because many core mechanisms are locked behind the tech tree.
3. Play kingdoms other than the duchy as soon as possible and unlock the tech tree further upward.
4. Only branch out and unlock other stuff when you actually get to the top of the tech tree.

Tricks:
1. Don't place your enemy tile when you can hold it on to your hand. 1 fewer enemy tiles is usually more useful than having an extra 3 perfect rows, unless you know you won't be taking any damage.
2. If you can draw some strong cards and place them early. Quickly exceeding the top and starting the "battle phase" early might be more beneficial most of the time (including the boss fight).
3. Quality of the card is always more important than quantity.
4. Check the enemy card before playing. If the enemies are stronger with a forest tile, then use lumberjack to make as few forests as possible and choose to use your card that would be strong on field.
5. SL is always available if you can't win.