Once you've done the 3x3 the 5x5 shouldn't be to difficult. The 4x4 will be much harder.
Is that a skill or a hobby?
So which one should I start with 4x4 or 5x5?
Adult coloring books. Theyre a great de-stressor.
What is the difference? A lot harder to color within the lines? The type of picture you are coloring?