Pencils, Sharpener, Kneaded Eraser, Plastic Eraser
i like to use mechanical pencils, and i have three 0.5mm pencils i keep on rotation on my desk or part of my portable sketching gear: a pink platinum preppy mate (thanks, gentian!), a uniball slim alpha-gel, and a uniball alpha-gel/kurutoga combo. they all have 4B leads in them, which i find is just soft enough and hard enough for me to use both on its own or with ink and watercolors.
for wooden pencils, i prefer the mitsubishi hi-uni line, though i have to admit i don't frequently use wooden pencils. for sharpeners, i use an x-acto knife and carve out the point so i can use the pencil on its side, but get a good sharpener if you can and especially if you like working in pencils. i'm all for saving money, but don't be that cheap on yourself.
two erasers are a must for anyone working in pencil: a kneaded eraser and a plastic eraser. i've used sanford design kneaded erasers for as long as i can remember, and i've yet to find other brands that can compete. for plastic erasers, i used to love staedtlers mars, but that's been kicked off the pedestal by tombow's mono erasers. and roundly.
does this sound like i'm favoring japanese products? it does, and i'm not sorry. they're simply made on a level far above and beyond what i've found currently on the market.