[mettamage]

Mobile friendly version (I am on mobile now, I hope HN changes this part of their design, bullet points should be mobile friendly, enough users complain about this, what happened to make what users love?):

simplify by eliminating everything from the problem except the essentials; cut the problem down to size

seek similar known problems, find analogies and apply solutions to your problem

try to restate the problem in just as many different ways as you can

generalize the building blocks by trying to apply them to broader class of problems

structurally analyse the problem - break it down into sequence of smaller mental leaps

invert the problem and see if it's solvable by retracing from solution to the start

[mettamage]

@mods: this got 40+ upvotes as of writing this reply.