Big is better
Only send photos of 2-5MB. Hint: When emailing, your device will ask how big you'd like to send the photo. Choose the option "Send Actual/Original size" and cc the photo to yourself to check your work. Mobiles can definitely take nice big photos.
Because you're sending us big files, cull your photos and send us just two or three, perhaps in separate emails.
Let there be light
We can't use shadowy photos.
Name and rank
Send captions naming the pictured people or at least the important ones.
Send photos to firstname.lastname@example.org.