FOR / TO

Use for when someone benefits from the action, and use to when the objects moves in the direction towards something or someone, like this,

I brought a chair for Sam. ('Sam' benefits from the action.)
I brought a chair for myself. (I benefit from the action.)
I brought a chair to the table. (The chair moves in the direction towards the table.)

I made a cake for Pat. ('Pat' gets the cake! Pat benefits.)
I made a cake to Pat. (Ungrammatical. Use a movement verb, like 'give'.)

I gave a cake to Pat. (The 'cake' moves in the direction towards Pat. Pat also benefits, but don't use 'for'. The verb 'give' already has the meaning of benefit within its meaning.)

I wrote a letter for Pat. ('Pat' benefits. Someone else did the work.)
I wrote a letter to Pat. (The 'letter' moves in the direction of 'Pat'.)

I will buy a cake for Sam. ('Sam' benefits. Someone else does the buying.)
I will buy a cake to Sam. (Ungrammatical. 'buy' expresses an exchange of items (money and things bought) so 'for' is best.

Try these out with other verbs and see what you come up with. If you find a verb that doesn't fit into the above patterns, post it here and we can talk about it.

Regards! Fabricio Santos