[fanaudical]

These may seem "lame", but are my top 3 and have saved lots of grief along the way (it took me a long time to learn these the hard way):

My #1 Tip/trick - Regardless of what you're trying to take apart/fix/repair/build, somebody else has done it before and mostly likely documented not only the pitfalls but the easy way to do it. Save yourself some time, money, and aggravation and do a little research before opening the toolbox and learn from the mistakes of others. Contribute something back when it's appropriate. (Of course, you must also review all the info you find carefully and think through things to make sure the info you've found is worthwhile...)

My #2 tip/trick - Keep parts and tools organized; take lots of pictures during disassembly and reassembly (you'll be surprised how often you refer back to your pictures of the reassembly to make sure you did something right).

My #3 tip/trick - Always assemble nuts/bolts finger-tight as much as possible to verify threads are good and parts are aligned before applying torque. If you can't get more than 1-2 threads with fingers, something may be wrong (or you're using mechanical interference fasteners).