I usually wear compression socks and quads an evening before the race and It looks like it helps, or at least I have a better feeling in my legs when I do that.
I’m planning to wear them much more especially when I found out that compression doesn’t prevent training adaptation.
So my question is when do wear them? After every hard workout? Or even before the workout/race?
Whether it’s right or wrong I tend to wear my TT compression socks during a race and I sometimes keep them on for a bit after the race. I’ve never thought about it the night before though.
When I ran I used Skins compression tights for all races and workouts in the winter. I also used their half tights (shorts!) during the summer with a pair of compression socks. I found it helped warm me up and although anecdotal I seemed to have less issues with calf strains when I used them. For TT I use to use Nopinz calf guards which have some compression - now I use Castelli fast feet which are long but not really compressive. I don’t find it makes any difference either way. That said of course my Nopinz flow suit I race in is very compressive I have to take a very deep breath to get into it! 
I’m not wearing them all night, I put them in the evening and have them for an hour or so.
I know the evidence is so vague in regards to compression clothing and its benefits but I find that wearing compression socks really helps me during heavy training loads and when I need to really focus on recovery. I wear them when I feel my legs are painful and restless and therefore may affect my sleep, I find putting them on for the night really helps as long as I keep cool, likewise, I will often wear them In the run-up to A and B events to aid recovery.
What about wearing them while driving to a race?
I don’t wear them when I ride, but every day post-ride and when I’m sitting at work to reduce fluid buildup in my feet and ankles.
Dylan Johnson did a video about recovery and mentioned compression socks. If I’m remembering correctly, science says they do not help performance during a race but do help with recovery after a hard effort.
yeah - never felt they helped with performance but found they helped with injury prevention…so I guess it is performance enhancing in the long term.
Current state of knowledge:
For me there a only a few proven (niche) areas where I see evidence. And I actually fall into one of these niches with running a lot in the mountains. I would extend this to all runners. For cyclists, not really. Not before, during, or after.