OK so I just turned 65 today, and I've only been playing for a few months. AND, I probably know less then I should about everything. That said...I still have something to say, and maybe it will help.
Here is what I think I've learned about Skirmishing, solo, Duo or Fellowship.
1. Start as soon as you can.
YES- you will advance rapidly and be able to equip yourself with nice armor and weapons, then as you progress you will also note that with all the skirming that you are honing your tactical skills and methods. You are also treated to being able to battle interesting and difficult mobs.
2. NO- Outside of the skirmish you will find the various quests and deeds less difficult, and less difficult is BORING. You will find that you have left epic story quests behind, and you can't move forward at later levels with out going back and completing them. Not to worry, you can hide your deficiency behind "helping" lowbies.
Other thoughts: I prefer duo, over solo or fellowship, I like leadereship to be defined clearly, and either I am the boss or my partner is. I would like a better understanding of how to earn marks (do NPC's that die cost? I bet they do).
I went with the first choice at around level 26-27, and began a march to 65 that took about 1-2 days for each level (depending on time to play).
I am glad that I am at 65 now, I get to go on all sorts of raids with my fellow kin, but I think for my alts, I will be taking my time, and getting to know the world that the dev's have created.
Thanks, I'm having a great time. So, if you haven't skirm'd or you like it as much as I do, look me up weekends early (5am-9am est).
Timate, Capt., Shadows of Eriador