Creating interesting transitions for slideshows that are easily repeatable

I'm mostly a still photographer although I dabble in video a bit.  When I come back from a trip, I have the urge to show my photographs to others and the only way to show a group of them that I can think of is with a slide show along with some interesting music.  To make this more than just boring flipping through images, I'd like to make unique transitions.  I have a few ideas of what I want to do but the bigger problem is I'd like to create a set of transitions that would be "easy" (however you want to define that term) to apply much like the video transitions in effects is done -- grap a transition and drop it where two clips (or slides in this case) meet and you are done.  It doesn't have to be that easy but the hope is to make it so that I can apply the transition.

For example, one idea is to start with the desaturated edges of the image and then fill the edges and re-saturate the image.  Or, have the image start desaturated and then using masking (I guess) remote the area that is desaturated as if it was being wiped away.  The first one I've done at least a "proof of concept" of it but now the question is how can I make it so it is easy to repeat?

Also... I mostly do Premiere Pro but if using After Effects would be better or easier, I'm game to do that as well.  This is 100% for non-sense fun (currently at least).