The final speech is your last chance to communicate your points to the judge – this is the only chance you’ll get to have the final say and convince the judge that you’ve won.
In Lincoln-Douglas and Policy, the final speeches are the 2nd Negative Rebuttal (2NR) and 2nd Affirmative Rebuttal (2AR).
First, go for less. It’s virtually never strategic to “split the 2NR” in Lincoln-Douglas, given that the 2NR precedes the 2AR (which can collapse to whatever the 2NR missed. This is doubly true for the 2AR. These speeches are just too short to go for multiple arguments. The speech needs to go for one core “path to the ballot” and spend the rest of the time weighing it, along with answers to the other side’s core arguments.
Second, slow down! Debaters sometimes treat the final speech as a shorter version of their rebuttal, which is a mistake. This speech is about communication, because you don’t have another shot at getting your point across. If an argument is unclear in the final speech, it won’t ever become clear for the judge, at least not on terms favorable to you.
Third, think of the round in terms of “voting issues” – while you don’t need to use the phrase, it’s useful to think of the ways that the judge could vote Aff and could vote Neg. Then, focus your time on crushing the opponent’s “voting issue” and winning your own path to the ballot.