I recently made a wedding cake and it turned out really well. but when i was cutting it. some parts of the cake just started falling apart. and i made a pillow cake and when trying to shape it, the cake was crumbling on the sides. what should i add when i'm making the cake to make it so it's easier to cut and form?

WASC is a good cake to use when there is carving involved. You can find it in the doctored cake box recipe section. Also, carve your cakes while they are still frozed and that will help tremendously.

I agree with msulli10. Exactly what I was going to suggest.

also use a really sharp knife, makes a world of difference.
xx

If you use a cake mix, mix in a half a box of instant pudding (the powder) to it right before you put it in the pan. It makes it thicker and it cuts and tastes better in my opinion. HTH!