I think I've reached a point where 99% of games require no "risk", in the sense that I never have to click a tile unless I'm sure it won't kill me.
There are a lot of patterns to find, and logic tools to use to map out the game. But I think the biggest piece is strategy: surviving and/or getting a high score without guessing requires that you explore as much of the map as you can while using as few health scrolls as possible. This allows you to find the gold, gnome, and necromancer to boost your mas health before using up most of your health scrolls.
You can explore without using health by marking the values of tiles and *not clicking them*, but instead using them to determine the value of neighboring tiles. You click any zero value tiles, and continue until you can't anymore. Then you click the lowest-cost tile that will bring you closer to the next corner you haven't explored yet. Repeat.