I often use spinner baits and buzz baits and I have not been using trailer hooks until I borrowed one from a friend and caught a 5pounder on just the trailer hook. What size trailer hooks should I use for buzz baits and spinner baits. 

use the size you borrowed from your friend

funny. I don't know the size that's why I'm asking 

It's probaby a 1/0 or 2/0 but if there is a tackle shop near by that sells them I'd take that hook it and match it up to find the right size

Just get some 2/0 and youll be fine

I've bought a few different ones and don't even know what size they are. They all work for me. 

Sometimes they effect the action of the buzzbait and I take them off. 

I own a single pack of trailer hooks, they're 2/0 Gamakatsu, and they saved my bacon earlier this year.

Nice fish. The trailer hooks are good for when the fish are just swiping at the bait

I use them quite a bit   on buzzbaits because it doesnt effect their snaglessness much and  a lot of bass are caught on the trailer  . i rarely use them on spinnerbaits because I throw them in tight snaggy cover and feel I will catch more fish without them . I like the ones in bluebassers photo , they stay straight pretty well .

I believe the ones I have are 2/0, I really don't think it matters all that much though as long as it doesn't affect the action. 

I use trailer hooks when fishing buzzers and spinnerbaits with braid. I feel they make up for the no stretch of the line and the number of fish I catch on that trailer reinforces that logic.  The only two times I don't use one is when fishing weeds and when slow rolling

I usually use a 2/0 gammy that comes with short peice of tubing. On spinner/chatterbaits i place tubing over stinger hook eye and then hook onto lure. On buzzbaits i put hook on lure then tubing so it swings and hangs a touch lower. Its just a personal preference to me. I feel i have better results this way.