LOL, that is a good one.
Well, being level 45 and no need to grind for xp anymore, this is what I do.
I do my daily in the B'Tran cluster in hopes of getting purple weapons and items for my ship and away team.
I do the defend missions against the Borg.
I chill on Vulcan trying to pick up on one of the natives. I frolic on the shores of Risa (two fist pumps!)
I help my fleet out with other missions.
And then: I use my starter ship (Constitution class from pre-order) to go fly around doing high level missions.
And last but not least: I warn people about where to put their experience points because by the time you make Admiral, you just don't have the points to put into Anti-proton weapons. So I was happy that I had enough in Poloran and Quantums.
Cancel your subscription and put off STO until there are respecs and endgame content. Or roll Klingon and pvp, or play through the game again on a new character class that has all of about 4 different abilities than the one you already played.
Not trying to be harsh, but there is nothing to do.
There is no endgame content to speak of and it looks as if it will be quite a while before anything fresh is made available to us. Pity the poor Klingons, who after a few low-level "training" missions have nothing at all other than repetitive PvP.