i'm pretty sure these are not repeats. if they are. oops. i found the scan in my computer and it would be challenging to find the actual envelopes so...i know that the bottom one is probably from janet. wavy lines are always a good way to start. drawing the beverage in front is another good idea. she colored in between the lines, which is one option, you can also color in between each letter.
the top one must be from cathy, since it is from madison. that white really pops on the envelope. the thin line of color around the edge of the envelope is a nice accent and ties in with the stamp design.