Having turned wrenches for 20 years, I’d like to think that I can pass on some tips.
1)HEAT-works wonders. Most people are not paitent enough, so they don’t think it works. I’ll heat up exhaust hardware until it’s glowing, spray with PB, loosen, repeat, etc. Let the heat work for you.
2)The aforementioned PB is PB Blaster penetrating oil-‘staple’ of getting shit loose, ha. Give it time to work and apply it several times before working on whatever.
3)Tighten before you loosen-Yep, you read it right. Sometimes if you tighten something before you loosen it, it’ll have a better chance of coming apart, not rounding the nut, etc.
4)Valve grinding compound-Works WONDERS in philips screws.
5)Two people-If you’ve got room, adding a 2nd hand on a long philips screwdriver will often times get a fastner out that you think is stripped out
5)Vice grips-Nut, Bnut, bleeder rounding off? Grab that son of a bitch with vice grips. It needs to be replaced anyway.
6)Impact tools-I firmly believe that the ‘knocking’ of an impact tool gives something a better chance of coming apart, vs a breaker bar or whatever.
7)Double nutting-no, not what I do in bed. Some kids don’t know how to get studs out. Put two nuts on it, tighten them together, and back it out.
8)Tighten, loosen, tighten-sometimes after you break something loose, it’s best to loosen it a little, tighten it, loosen it, tighten it, etc. I mostly use this technique on rusted hardware. Feel free to throw in liberal amounts of PB here, too!
Just some off my head, feel free to add!
EDIT-added one