I jog around my apartment instead of standing in place.
The Balance Board gets dirty even if I wash my feet before I use it; there's no way I'm letting everyone else who tries Wii Fit going on without socks. I wear tiny little socks that cover just the soles of my feet when I exercise.
I was doing the downward facing dog posish the other day and the Balance Board actually moved on my carpet. I couldn't keep it steady. ANNOYING.
KDR: Some of the ratings, as you know, are useful (I think most of the yoga scores really do reflect how well you're doing the position). But I'm totally with you: I can get 100s on some of these things really easy, even though I'm weaksauce in general.
One KEY thing to exercising and doing yoga with Wii Fit is to have a friend or family member watch you. There are some exercises where I could get a really high score, only to realize that I was doing it entirely wrong. I spend half of my time with Wii Fit now watching my trainer and making sure I have the same posture. Exercising in front of a mirror is another solution to this problem.
Especially tricky are the last two strength exercises that involve the Wii Remote. I have no idea HOW I'm supposed to be holding the thing, so how do I know if my score is really accurate? I can twist my wrist around a bunch and get a different read from the system, too.