I didn't have a lot of money, so cutting arms and legs off of your little plastic (or lead) fellows might just turn a perfectly good mini into so much junk.
Luckily for me, I was (am?) kinda good at it and the original plastic space marines were modular and practically begging to be converted.
One of my first attempts was a leader. I was inspired by this pic in the back of the WH40k Rogue Trader book --
I also tried to make some guys with "combi-weapons." Was that a thing back then? I don't remember... These aren't too spectacular, but you can see I went a little crazy converting bolter accessories into armor bits. "Chainsaw shoulderpads" on both models...
I think I originally wanted the guy on the right to have a Meltagun. I used an aluminum standoff as a giant muzzle on his converted bolter.
I have a bunch more of these that I will share in future posts!!