I’ve used the foam ones, still do for sleeping during the warmer weather when I have my window open, or if camping, but I do find they irritate my ears a bit.
For gigs I prefer the triple-flanged silicon ones, they sit well into the ear, and are easily washed.
You can get them from Amazon and the like with filters that block specific frequencies but allow conversation, cost about £15 I think.
I’ve just got a couple of pairs from Massdrop, cost $11 a pair, but I’m yet to try them in an ‘aggressive environment’!
I’d like custom ones, but I also want custom eartips for my Meeaudio canalphones, which are going to cost at least £120, so I’ll use the cheap option for the foreseeable.
There’s a whole bunch here: https://www.amazon.co.uk/Ear-Plugs-Hearing-Protection/s?ie=UTF8&page=1&rh=n%3A340837031%2Ck%3AEar%20Plugs%20Hearing%20Protection
Mine are Rooth ones, they do full custom as well, but I can’t justify the cost for the amount I’ll use them, compared to how much I use my earphones.