If you can, try to focus on the few best arguments, and win on those. In TP finals of Region 10's first qualifier, the negative team (who have a combined eight years of debate experience) spread out the Affirmative with 5 DAs. The problem arose when the 1AR adequately addressed all the arguments. In the 2NR, it was evident that their strategy had backfired. In addition to making it harder for the affirmative, they also made it harder on themselves. They didn't have time to go over all the arguments in the 2NR, and lost on a 6-1 decision.
Bottom line: The best strategy is to go in-depth on a few main points.
Many experienced debaters endorse the shell-and-extend strategy, but that's a rather difficult strategy for a team of your experience level. If you can do it, go ahead, but I wouldn't worry about it too much. (My brother and I have a combined six years of debate experience, and we still need to work on it ourselves.
) So I would hazard a recommendation of something I came up with as I wrote this post. It's along the lines of a mix of shell-and-extend and splitting of the negative. Basically an in-depth splitting of the negative, if that makes any sense. I don't know of anyone who does this in practice, but here's how I envision it to work:
1NC: Focuses on a couple main arguments, and provides warrants and compelling reasons for the arguments.
2AC: Responds to above
2NC: Brings up two or three new arguments with similar structure to 1NC
1NR: Responds to 2AC
1AR: Now must refute all warrants and analysis in five minutes, which can be done but is difficult
2NR: Responds to 1AR; provides strong closing arguments to judge
2AR: Desperation attempts to sum up round fail
Again, I haven't thought about this type of strategy a lot. There is probably a major hole with it somewhere, but I don't know where. We don't do this strategy (we try to go by shell-and-extend), and neither does anyone else I know of, so there's probably a good reason why.
Barndt/Barndt | TACT, R10 | 2012-13
Barndt/Barndt | TACT, R10 | 2013-14
Barndt/Barndt | TACT, R10 | 2014-15
Barndt/Blacklock | Arete, R10 | 2015-16
Barndt/Cuddeback | R10 | 2016-17
Barndt/Wolf | SALT, R10 | 2017-18
I'm inclined to think like Andrew does.