I have to admit that after 5 years of swimming for fitness, I finally figured out how to count. I do the same a Lise- with every stroke, I just count. 1,1,1,1...
etc. That way, I am not getting lost/confused. Also, I came to the realization that during a race, there was no wall to touch, that the swim was continuous ( don't laugh, I can be slow), so I didn't want to stop all the time to move pennies. Train like you race-race like you train...

Best of luck to you... let us know what method works best!!!