Personally, I have the issue where using /home - when it works, what with my lag issues - often loads everything except the chunk I'm in, leaving me stranded, falling into a bottomless pit and being re-positioned at ground level every few seconds. So what I did was create a private "home" warp point that was a chunk or 2 away from my actual /home point (the /home point is right in front of my main entrance; the private warp point is inside my house). So now, when I find myself falling endlessly at my /home point, with all the other chunks around me loaded, I just "/warp home" and it instantly places me in the already-loaded chunk inside my house.
I second what people said about using stone tools; the only times I use a diamond pickaxe is for mining obsidian and
sometimes for carving out large construction areas; all the rest of the time I use stone wherever possible, and iron for those things that need it (redstone, gold, and diamond). The major advantage of stone tools is that they're made out of fully renewable resources, and aside from building structures, stone isn't used for all that much anyway; not so for iron, gold, and diamond.
The major exception to all this would be a diamond sword while spelunking (or otherwise anytime you expect to deal with hostile mobs). The immediate benefit of increased damage, and therefore less potential damage to you, is well worth it.
IMO diamond armor is never worth it during regular gameplay, as it uses up far too many diamonds. If it protected the user from falling into lava, I'd be all over that, but since it doesn't, then it gets completely lost far too often. Also, from what I read about the way armor works, it seems that diamond armor will not reduce any more damage
per attack than iron or even leather armor - it simply can endure a lot more attacks.
