Inspired by Kaesae, I made a split collet extractor for the Horst link bearings on my Stumpy using an old V-brake boss and a random bolt. Worked like a dream on a bearing that hadn’t been touched for 7 years!
I use the decorative end of a curtain rail + threaded rod to seat star nuts.
Bit of plastic plumbing pipe to seat Pro 11 seals.
Drinks bottle compressor to seat ghetto tubeless tyres.