I coil them tightly around a 3mm hex driver shaft. I generally apply very firm pressure & use friction heat by rolling my fingers around the wire & shaft to tighten the coils.
It works very well.
As for the mounting of the receiver, I'd use a piece of lexan double sided taped to the top plate & tape the receiver to that & then use a thin cable tie around just to be sure.
This was taken with my friends ESC, which has now gone back to him. I'm still waiting on my 6 MM's to arrive as the last lot they sent went missing somewhere. Not happy about that, but, thieves are everywhere!!
Losi SCTE SC4 Pro 4000kv, Tekin RX8, 2S
MP7.5 Kanai III Tekno Neu 1515/2.5D 1700kv MM 4S
LST 2 Carbon CC 1717 1Y 1580kv MM 6S
Futaba 3PKS Spektrum Pro