Most jobs only need three tools; a hammer, duct tape & WD40.If it sticks and it shouldn't, WD40. If it should be stuck and isn't, duct tape. Otherwise get the hammer out.
Essential tools.For most of my projects a basic tool kit containing screwdrivers, pliers, side cutters, hacksaw, wood saw, a drill & bits is a good start, also a set of spanners and a socket set will come in handy. For the electronics projects a basic soldering iron and a multimeter at least will be needed.
These tools are not entirely necessary but will make life so much easier.
Jigsaw, invaluable for cutting curves and large diameter holes.
Reciprocating saw, not at all necessary but saves a lot of time.
Arc welder, very handy for quickly joining steel parts.
Angle grinder & discs for cutting & grinding, for grinding angles of course.
Hot wire cutter, for cutting polystyrene.
Rotary multitool, for all the fine work.
For the electronics projects although it's possible to use a basic soldering iron a much better choice would be a low wattage, 15W soldering iron with a grounded tip or even better a temperature controlled solder station. For scavenging components from circuit boards a desoldering pump makes removing components much easier.
Safety glasses/goggles and dust masks are an absolute minimum but I would also recommend a pair of decent work gloves especially when handling hot or sharp objects.
For the high voltage electronics projects try to ground all accessible parts and most importantly have an earth leakage circuit breaker (ELCB) connected between your power tools and the project, and the mains electricity.