I use Virbac's Epi-Otic
Virbac Animal Health — EPI-OTICŪ Ear Cleanser | United States
I just squirt some of the solution into each ear and massage it a little and let the pups shake it out...after another minute I take a cotton pad and wipe out the outer part of their ears to remove any loosened gunk that has liquefied and gotten shaken out. I'd definitely stay away from the q-tips or just use them on the very outer part of the ear (it would be better to just use a pad over the q-tips anyway so you won't have to worry about mishaps). Q-tips aren't really even supposed to be put in our ear canals either (even though I still do it...)...an ear drum could easily be ruptured especially if you have an uncooperative, squirmy, or spooked pup.
I try to coordinate ear cleanings with baths (since the cleaning solution we use contains a drying agent) so ears get cleaned maybe every other week or so.