Haven't read all the replies, but this is something I have much experience with!
I eat salad for lunch every day. Yep, every day. I spend a little bit of time each evening prepping it. So here's the plan:
Sunday:
wash lettuce/ greens, spin them dry, put them in a ziploc bag with a paper towel (keeps it fresher - moist but not damp)
prep vegetables (whatever I have that week): peppers, carrots, cucumbers, celery, snap peas, whatever. 3 days worth usually, but sometimes 5 (you know, sometimes they get weird by day 5). Put in a container or baggie
prep protein and/or carbs. This may be as easy as making sure I have sliced deli meat, or leftover chicken. Or it may mean hard boiling a bunch of eggs, or having some canned tuna or salmon. Or cooked beans or canned beans.
make salad dressing (olive oil and vinegar, or sometimes something more exotic)
make sure I have some nuts/seeds (I use 2 tbsp a day of sunflower seeds, almonds or cashews)
crumbled cheese sometimes if it's there (blue, feta) or olives
Each night:
Put a Tbsp or two of dressing on the bottom of my salad container/ tupperware. Next comes the protein, veggies, and beans on top. They form a wetness barrier. Then cheese. Finally, the greens. I put the seeds or nuts in a separate container because I like them dry and crunchy.
The next day I shake up my container and eat out of it or dump it on a plate, and top with the seeds.
Sometimes when my spouse is traveling and I'm alone with the kids I may prep 2-3 days' worth at once. I've never tried a full week.
I keep it fun by changing the dressing each week, or the bean, or the protein, or the veggies. Within the week it may change too. With this method, the veggies are already cleaned and cut into strips, so all I have to do is chop a small handful.