Another tool of mine that I use fairly often, is my Dremel. It comes out every 3 weeks or so, for some akward job, that would take twice as long without it.
I got so much stick from the guys I work with when I bought it, but now they borrow it. Diamond blade on it...double handy. I used it on Friday to grind down a horseshoe from a monoblock tap. The bidet had a fault in the porceline and the horseshoe didn't fit. 5 mins later, job done.
The other thing I love is the wet vac. I also use a tool called a Rad Wrench. Which is a powder coated tool, for supporting rad valves, as you loosen the unions. When I picked it up from the merchants, another plumber snorted 'that's what grips are for'.
True, but in posh houses, valves on a ladder rail easily cost £100, and I don't wanna risk scratching them.