I think there is no general rule, because it may depend on vulnerability. White vs red or white vs white for take out, red vs red for penalty. This is matter of partnership agreements rather than what is better/more frequent.
Yes, you bid 1M first with 5+d & 4M. You need to have some methods here as well but these are quite easy. If fit hasn't been found then 4nt should be natural quantitive I guess. If you are stronger than that, you can pretend and set ♦'s ...
I haven't mentioned about one more solution in 1♣-2♦ sequence. You can play that 2♦ denies 4M (2♣ does not, as there's more space). Bidding is much more comfortable now:
2M = 18+ 5+M
2nt = 12-14 or 18+ bal/semi bal ...
Common standard in Poland for 1♣-2♣ is:
2♦ – 12-14 bal, may have 4M (now responder may show 4M) – Gawrys-Klukowski play that way
2♥/♠ – 18+ 5+M
2nt – 18+ bal/semi-bal may have 4M
3♣ – 4+ clubs, denies 4M, doesn’t promise extras (this can ...