I often need to create bleeds for designs that include photos inside of clipping masks, and I currently know of only two ways, neither being very speed-efficient.
Method 1 - Reposition all four edges one at a time
This is for rectangular paths. With the Direct Selection Tool, in Outline View, click on one edge of the path, hit Enter, and specify some distance to move the edge on the X or Y axis. Tedious because it needs to be repeated four times per mask, and accidentally clicking a point instead of an edge can lead to error.
The animation above makes it look like a quick process, but as the number of images increases, the time required adds up to a significant loss in productivity.
Method 2 - Offset the path and rebuild the clipping mask
This is mostly for paths with arbitrary shapes. With the Direct Selection Tool, in Outline View, click on one edge of the path, click anywhere on the path, and choose Object > Path > Path Offset and specify the distance to offset the path. This would be great except that Illustrator assumes you always want to keep the original path unmodified and add a new modified path under the original. The clipping mask is still using the original path, and the new path is just sitting under the original, disconnected from the mask. So it is necessary to remove the clipping mask, then delete the original path, select the new path, and recreate the clipping mask. This is about just as troublesome as Method 1.
There must be a better way? Perhaps a way to offset without creating a duplicate path? I'd like to hear what tricks/suggestions the community might be able to offer that I haven't thought of. Thanks.