When was the last time you took engine assistance to check a position for the correct evaluation? How often do you do that? If you feel that you want to get your habit of checking engine under control j will recommend you to solve studies. So what are studies? Studies in chess which is also known as compositions in chess are unique positions. These positions are very instructive for the following reasons
1. They have a forced win.
2. There is only one solution to the position.
3. The idea is not so obvious
4. Each time you learn a new pattern
5. There are a lot of positions which engine cannot solve which proves that nothing can substitute a human brain!
6. There is no restriction to composition.
So basically studies are widely used as a tool to a calculation by Grandmasters and also they recommend studies for improving calculation. Solving studies is a lot of fun as there are a lot of lines with best possible Defence and after hitting them, then you reach to a solution which is the correct answer.
I will recommend Domination in 2545 endgames by Kasparian. The positions are structured patterns.
Try solving the following position