Just need reassurance it gets better!

I have a 7 month old mutt (maybe lab mix? maybe boxer mix? maybe pit mix? who knows). On the whole he's great; we love him to bits. I just get so frustrated with the nipping. Constantly. And we're doing everything we have been told – get a toy to redirect it, if we can't/that doesn't work, do the reverse time out. Doesn't seem to matter. You're sitting there and he wants to? Nipping. Walking down the stairs? Nipping.

We've been better about enforced naps recently, but it doesnt' seem to help. I just need some kind of reassurance about the landshark phase!