Slip the bands ASAP. The window of opportunity is small. Then they just wont go on,, 
The mother will try to pull the bands . It happened to mine many times.
I used a small piece or yarn around the band to make it tighter/smaller so it does not slip off. Slightly tedious and usually a 2 person endeavor. After a couple days the leg grew soo fast, the yarn was no longer needed. I removed the yarn.
I have not tried this, but considered using athletic tape on the babys foot to separate the toes and create a fan shaped. This way the band would not slip off.
I usually just kept putting the bands on each time I noticed them off.

The mother will try to pull the bands . It happened to mine many times.
I used a small piece or yarn around the band to make it tighter/smaller so it does not slip off. Slightly tedious and usually a 2 person endeavor. After a couple days the leg grew soo fast, the yarn was no longer needed. I removed the yarn.
I have not tried this, but considered using athletic tape on the babys foot to separate the toes and create a fan shaped. This way the band would not slip off.
I usually just kept putting the bands on each time I noticed them off.