For +1 you need 9-10 Increase Enhancement rate

For those interested, the +2 version of this outfit gives Fishing Level +2, Movement Speed +2 & Fishing Exp +15%.These are in high demand on Uno NA, being snagged nearly immediately after being placed on the marketplace. As such, I ended up building my own because I do a lot of fishing.

I'd highly recommend getting +2 as they're pretty cheap, but stay away from anything higher. You have to get to +5 before you get another Fishing Enhancement level.

I found this to be ok,

+1 costume i will smash at +0 get about 30-40 of them
+2 costume i will smash at +17 push it to +20
+3 costume i will smash at 26-30
+4 costume i will smash at 40-44
+5 costume i will smash at 60-70
Someone posted this on the BDO forums and it seems pretty good to follow.

But i actually do this...
5FS +1, if it goes to 10FS, go for plus +2, if it goes to +15 Buy 20 Advice for Valks and save it.
20FS for +3.
But i havent gotten any further than that as of yet.