I recharged my Pebbles while I was in the shower, since they usually took less than 15 minutes to top up after ~24 hours of usage. I've found my Apple Watch (it is an older model, though) to need too much time to recharge, however, so rather than building a different habit around it I recharge it overnight.

I tried for years, didn't work for me (Apple Watch 2). I mow have a Garmin Fenix 7 which lasts 18 days without recharge, buy has much more limited features (which is fine for me).