Print Sizes Offered and Aspect Ratio

What do you guys/gals do with regard to showing proofs to clients & aspect ratio?

I mean, if I offer a choice of several sizes, then the image they see in proofs may change slightly depending on the aspect ratio. I'm just what the best way is to offer proofs:

1. at 'out-of camera' ratio w/ a disclaimer that actual prints may be slightly different.

2. Crop all proofs to an 8X10 frame

3. other suggestions?

thanks,
daniel

Based on the photo studio i work at and what i've seen said around here

Most, if not all proofs are 4x6 (2:3...ie your camera)

I guess it's up to whoever is pritning it to crop it as needed.

Well, no not really.

If I put 100 proofs online, or give 100 4X6 proofs to a client and they decide they want #'s 3, 5, 34, 29 and 87. Two of those being 5X7's, and Three being 8X10's. So, now they've seen 2:3 ratio (4X6) proofs, but they want 2 different aspects.... Now, imagine that those photos were filled-frame photos that would lose valuable parts of the image by cropping to the 5X7 & 8X10 ratios.... So, what then? If these photos are sent to a Lab...they are just going to chop off the top and the bottom and send them. Its up to the photographer to crop the images correctly before taking them to the lab.... I'm just not sure how to work it into my workflow... and what ratio to show to clients as proofs.

-daniel