Gripping with thighs...you were taught differently to me. I was taught to relax my legs and sit deep in the saddle. I learnt on a very bouncy horse so I found it quite hard to sit at first. Just like when you're doing a sitting trot relax your legs, lean back and sit deep in the saddle, then all you have to do is practise, practise, practise. After some time youll be able to sit a canter perfectly well, all it takes is time and practise.
If I am not riding I'm thinking about horses, and if I am not thinking about horses I'm riding