we just stood him up against the tree and saw how tall he was and then hung ornaments higher than he could reach. it looked funny but we didn't have to deal with him pulling them off.
I just did ornaments from my waist up. Never had a problem. This year with a 27month old and almost 4 year old and ornaments down low I am having problems. As the bring me ornaments they have pulled off I just put them back on a higher branch.
Re: Christmas tree/15 month old question