Ive been working low singles alot lately, and its been an effective takedown, but I have problems working submissions from it. I've been trying to pick the ankle and sit through to a scissors and take an ankle or a kneebar... any advice as to easier ways to gain an advantage?

Are you ending up in guard? If so work on passing the guard. Going straight to a leglock from a low single is a little odd because the person you took down still has a lot of options in a sub grappling environment. what I mean is you don't have a ton of control over someone immediately after the low single. You need to establish a position first.

Listen to Whiteshark. It's more important to establish your control over your opponent than to dive for random submissions. If you drop back for a leg you're pretty much just giving up top position if you don't finish it, and against most competent people you won't be able to finish it.

Position before Submission!

Thanks for the help guys, I tend to get caught in half guard rather than anything else, although there is one asshole that tends to get a butterfly in pretty consistently. Appreciate the advice.

Are you ending up in guard? If so work on passing the guard. Going straight to a leglock from a low single is a little odd because the person you took down still has a lot of options in a sub grappling environment. what I mean is you don't have a ton of control over someone immediately after the low single. You need to establish a position first.

Yea, hit the low single then solidify your position. You'll be much better off then trying to go for a leglock most of the time.

Half guard from low single? I'd go straight into a sit back pass then.
Like this:
http://www.youtube.com/watch?v=HL2tTtDHRs0&feature=related