Solving puzzles is fun. But figuring out the ways to solve challenging puzzles are fun too. So I'd recommend that
you try solving them, starting with the easy ones, and learn the art of solving on your own.
Anyway, if you got really stuck, here are a few hints you might try:
First of all: use the question marks
One important thing is the proper distinction of known empty cells versus the yet undefined ones (marked with
question mark). A cell, whose color can not be determined, should be kept undefined. The cells, which are known to
be empty, should be set to clear.
Using the question marks and empty cells correctly dramatically improves puzzle solving performance.
Find the obvious
Usually you may to start solving a puzzle by a few full sweeps (or scans) of all the rules, identifying the
obvious: finding the all-empty and all-set regions
empty and full rows/columns for GraphiLogic:
0-s and 9-er areas for Mosaic (and of course 6-es at the sides, and 4-s in the corners):
Check the neighbors
Once these initial sweeps are done, finding additional cells to set or clear are
getting harder. After a few more sweeps it's usually a better practice to remember where the last few changes
were made and check the rules involved with that change. In GraphiLogic, after you set or clear a cell of a row,
your first thing to do would be to check it against the corresponding column. For a Mosaic, you will check all
the numbers around the modified cell(s).
Puzzle specific strategies
Select a puzzle type for the specific solve strategies: