How to escape forks
Check which moves your opponent's pieces have, and if they are threatening to fork your pieces by checking which squares the enemy piece would control following a move. You should then, if at all possible, defend the square, or, if that is not possible without costing you material, move one of your pieces away so it is no longer a fork. It is best to use longer time controls to ensure you can think about this thoroughly without having a time shortage.
Always looks for checks, captures, and attacks. Pay extra attention when your king is on the same rank, file, or diagonal as another piece.
There is a shortcut that I have learned which can help to escape knight forks. On any given turn, a knight can only attack squares of the same color. So if two key pieces, say the king and queen, are on opposite colors, they cannot be forked (same goes for the bishop obviously). Also if a knight checks you, if you move to the same color square he cannot check you on the next turn, because the knights color always alternates from light to dark. This could help if you are in a time scramble and don't have time to calculate every possible move.
Try to know the possible patterns for forks and avoid putting your pieces in forkable squares
One easy rule, never put king and queen on same color squares, same diagonal or same column.
You can try to check your opponent's king and get your pieces out of the fork (unless the fork is with a king) or take the piece that is forking. If those don't apply, then try to move the more valuable piece away.
Thanks, Good tips! In addition to, "knights always move to opposite color square from where they start"...they also always attack the opposite color squares of the new square they land on.