Well this is just my experience but, all of my dogs have had to have coats ect, so i start when they are young, and i put the jackets around there bed, once they adjust to that then i will dress them and leave the jacket on for 2 min, give them a treat, small bite of freezed dried liver. then remove the jacket, then everyday i would do the same thing and in crease by a min, get them to chase and play.
Make sure the jacket is comfortable and easy to move in, you can try a fleece jacket or a t shirt.
Make sure nothing drags, or they can trip or if its too tight in the chest, or too loose to, so take your dogs shopping.
Walmart offers some great deals on cloths.. happy dressing
I have never trained my dogs to wear sunglasses, but if you have post a discussion here ok let us know how you did it.
now this is how your dog should not look, mom i can;t move!!