I've just started playing a lot of 1v1 online as well and it's pretty much a joke. Almost every single person just holds turbo and the defend or double team on defense and on offense it's always a long pass to the forwards who typically outrun my D. The sad part is is that I see it coming every time and can never counter well. It's like every person I play is the same person over and over again, same strategy every time.
Two things I need to work on, countering hyper intensive D pressure and stopping my opponent from getting such easy goals through long balls to the forwards. Part of me doesn't really want to work on these things though because the game I'm getting online (ranked) is so far away from anything resembling actual soccer that it's just getting lame to play. Occasionally though I'll run into a really talented player who actually has a clue and that's usually fun to watch them deconstruct me and my team.