you've got some good links and tips but a question, what type of line
are you using?
how long a leader? if you're fishing in clear water for spooky fish,
and if you are then
using a long leader (longer than 7 ft) than you really need to make
sure it is
tied right (stiff butt and good transition to the tippet), and matched
to your fly, in
order to turn over the fly properly. However, for a crease fly, I'm
guessing you're using a floating line? The problem with crease flies is
usually their wind resistance (that and they often spin too dang
much...)

what I've found is that I try to cast much to quickly, not allowing the
rod to bend (load)
properly on the backcast, especially when I get tired, and I don't get
enough line
speed . Then it's a real, and dangerous, mess on the forward cast.

re-reading your post, catching the water behind you makes me think that
you're just not stopping your rod properly and as others have written,
diagnosing
a bad cast is tough without seeing you in action.

however, my gut says you need some work on mechanics: double hauling
etc, to
get the line speed up properly, then you won't have problems with the
tailing loop
on the forward cast.

lastly, as a veteran lip-hooker myself, and as you doubtless are awa
go barbless!
to avoid unnecessary danger at night, I really open up my cast and
have a modified stroke (based on a suggestion from a fried) that keeps
that barb far away from me on the foward cast. It sacrifices some
distance, but the thought of another trip to the emergency room sort of
eases the pain.

-- Rob