I use mastik one, the conti glue sucks in my opinion.
I use one tube per tire... 1. brush on rim, 2. brush on tire 3. If about 15 minutes has passed since I brushed on the rim and the glue is tacked up nicely I then spread the remaining glue on the rim and put the tire on immediately and straighten and clean up any mess.... Then wait 24 hours and ride it. Should take about 30minutes once you've done it a couple times, I am sure some can do it in less.
You should not have to use more than one tube per tire.
1 Super Record bike, 1 Nuovo Record bike, 1 Pista, 1 Road, 1 Cyclocross/Allrounder, 1 MTB, 1 Touring, 1 Fixed gear