What are you doing on your 50s?
Dueling other 50-54 twinks, or 55+ non-twinks.
World pvp - e.g. controlling flags in Hellfire peninsula (annoy random lvlers because they can't complete
Hellfire Fortifications)
During hellfire pvp I met a guy who has even more 50-54 twinks than me, and had them long before the EU 50 project began.
So when doing 50-54 twink duels it is mostly with him as the rest of you aren't really active.. I just can't play so often because of work and other things.
At last I do the typical way to get some cheap action, XP-ON and WSG as long there are no flagcaptures.
There is also almost always some alternative BiS item for certain situations that can be spent a long time to farm for all of them. A very essential and fun thing about twinking is especially also the gearing and perfecting process with different sets etc.
I can't think of more that I do as "solo" twink at the moment, except for random dungeons maybe and as said further gearing/enchanting/twinking for alternative sets/situations.
It would be much more fun if we are just 2 active instead of 1, then wsg with a tank and healer and flag holding.. or if 4 active then it would be fantastic with instant arenas and especially when many of us I assume have more than 1 twink in the bracket so the possibilities and potential of fair and competitive 2v2 games woudl be greater and an infinite entertainment.