My 14 month old is just starting to walk and has clarks first shoes. They are velcro fastening which he has already worked out how to undo. When in the pushchair, he often takes them off and we have actually lost one totally. This meant buying a whole new pair - urgh! Since then, we have tried to be really careful. If he is going in the pushchair, we tend to take them off his feet completely. He also takes his socks off, but these I am less worried about losing.
Then today, in the pouring rain, I forgot to take them off him and yes - he lost another one. We retraced our steps all over the west end of london in the rain - not fun, but to no avail. Luckily, we had kept the other of the last pair and we lucked out that it was the right one to make a new pair if you see what I mean! However, at £16 a pair, I am terrified of him losing one again!
What can I do???? I do try to remember to take them off him, but when we are out and about, sometimes he is in and out of the pushchair and it is not always practical. I did not have this at all with ds1 - he never took his shoes or socks off!