You won’t need all the tools of an A&P mechanic to build your experimental kit aircraft but those you use should be in good condition and of excellent quality. 

3/8″ drill

small drill bits, numbered & fractional

extra #10, 20, 30, 40 drill bits

6″ & 12″ long bits, #30, #40, 3/16″, 1/4″

sabre saw with metal cutting blades

assorted files

hack saw

chalk line

plumb bob

carpenter’s levels – 24″ & 48″

razor trim knife

tape measures – 12′ & 25′

straight edge rulers – 1′, 3′, 6′

center punch

carpenter’s square

T-square

Clamps: vise grips, spring clamps, C-clamps

bench vise

sanding blocks – hand block, long board

pop rivet puller

scissors

ventilation fan

trouble light, fluorescent

hand tools: wrenches, screwdrivers, pliers, hammers, etc.

handshears (tin snips): offset handle style, one each-left cut (red), right cut (green) and straight cut (yellow)

Special tools that are a worthwhile investments and a great help:

Dremel Tool kit

die grinder – with drum sanding kits, cut off wheels and grinding stones

bench drill press

fiberglass cloth cutting table

epoxy pump

roller blade (rotary cutter) for cutting fiberglass cloth & fabric

2″ wide paint roller or wallpaper seam roller

manual rivet squeezer (saves time when installing nutplates and less violent than air driven rivet gun)

cleco pliers and clecos: 100 of #300 clecoes, 10 of #40 clecos, 10 of 3/16″ clecos, 6 special side clamp clecos.

THIS LIST IS NOT ALL INCLUSIVE BUT GIVES YOU A REALLY GOOD STARTING POINT.