I know no training session is "typical" but what would be a basic day for a junior level dog? I know you want to run marks, marks and more marks, but when do you start mixing it up with some other "fun" things, add, what would some of those fun things be?
OB drills, Heeling patterns. three handed casting drill, fetch/no fetch, FTP.
T and or TT work, depending upon the dogs' level
Pick and choose marking concepts that can be learned through repetition or attrition.
Cheat marks, Down the shore marks, crossing points, etc need to wait until after the dog is doing some basic handling.