Photoshop Cropping tool -Need some help! How can I force it to stay in the frame?

[Embdude]

Cropping tool -Need some help! How can I force it to stay in the frame?
I shoot baseball in landscape but sometimes with pitchers and batters it is nice to just switch to the portrait orientation. in many cases I just need to reframe the crop boarder without resizing it... however when I do this I almost always end up with a strip outside of the frame (even when I try hard to be precise). This is driving me nuts and slowing me down... how can I make it stay in the frame?

227640227641227642227643

[martiansea]

Turn on snapping?

[Pieter]

Particularly, snap to document bounds, unless you're trying to trim just a little off the edge of the image. Otherwise, first just turn on snap to guides and put a guide where you want that close edge to be, then turn on snap to document bounds and you should have no problem.

[Embdude]

This works! Thank you both so much!