Learn to shoot the drone. That's the most important part. You need to be able to shoot the drone when it starts ulting or otherwise you're royally screwed. And you also don't want to leave it hanging giving out info if a fight is about to start. If crypto is in the fight - the drone is not moving, so just find it and shoot it.
On the other hand, I usually leave my drone tucked in on roof or weird angles - so in this case, just ignore it. If you waste too much time to shoot it, crypto also wins.
Crypto also has no combat abilities (apart from the ult), so he's generally weaker than any other legend in simple combat. If he doesn't provide intel and the ult doesn't work, then he's just a legend with no skills at all.
Simply be aware that enemies know exactly where you are if a drone flew past and always expect an immediate ambush.
Although if you shot the drone - they probably won't push, since crypto cannot ult without his drone.
As for crypto lagging behind - t's not his problem, it's the teammates' that don't wait for him... So far I found him unplayable in unranked due to this reason and just barely usable in gold+ (ex-diamond+) ranked. So far I found the optimal way to play a crypto comp is with wraith - crypto goes in with drone, wraith goes in with portal, crypto ults and immediately goes into the portal. If the ult hits all 3 - it's practically a 100% win. So far managed to pull that off only once in gold ranked (with randoms), but it was glorious.
So again - try to shoot the drone, or you're screwed XD. If you do get hit by the ult, the most important thing is to not panic and act as if you were hit by an arc star. The most important thing to remember is that your sensitivity is significantly reduced when disabled, so aim much more vigorously.
I do hope ppl learn to wait for crypto, since he's really quite fun to play and has a powerful kit.