hi,
Let us repeat once more the methods by which we can increase our combinative skill:

"Let us repeat once more the methods by which we can increase our combinative skill:
"(1) by careful examination of the different types and by a clear understanding of their motives and their premises
"(2) By memorising a number of outstanding as well as of common examples and solutions
"(3) Frequent repetition (in thought, if possible) of important combinations, so as to develop the imagination."
-- Euwe, Strategy and Tactics in Chess.
Creating a file of positions, problems, studies and puzzles with explanations in your own words about the motives, ideas, analysis etc. should do the job.
Also I found out it is useful to train your vision
study the board and the movements of the pieces without the board and the pieces until you get a clear picture of what is going on
study the board until you do not have to think anymore about which colour a certain square is, you simply know instantly cause you got a clear picture in your head. If you know the battle scene, nothing should escape to your attention. Then start experimenting with the pieces. put a knight on a square and do some exercises in your head. which squares is it attacking? how many moves to reach a certain square? how many different routes to reach a certain square? You must simply know what is going on. your tactical ability will improve cause you do not have to think much long anymore about positions you know, feel or see...
