I know that you have to be level 40 to make your own Guild,
but what's the best level to actually make one?

uhmm id say 70.. if you'd like to guild war and such.. 70..is good unless... you want to make one which you know is "respected" you should be 100+ where you will get high levels wanting to get in.

when u have tons of ppl rdy to join with u

'Kay.
Thanks. ^^

I'd start at maybe level .... 100 or a little bit higher.