I like those sites. But, realistically, I usually don't make separate meals for lunches, I just repurpose. Bento is great for encouraging variety. I usually have a sandwich or leftovers (pasta or rice or something) account for 1/2 the box. I usually like to have a little container of vinagrette or mustard to add variety to things. Then I fill it up with different fruits and veg., maybe a few nuts or small piece of cheese. Finally, I like to add a little piece of chocolate or dried fruit to finish. I try and add just a few bites of different things laying around the fridge. Makes it more interesting and I don't waste as much food.
I pack mine and my kids lunches as bentos. We do all sorts of things - leftovers, sandwiches, salads, etc. I tend to do dry items in their lunches as their lunch boxes get tilted and liquids items can leak. I also use bento supplies like small shaped cutters, food dividers (waxed cupcake liner type things) to put several items in a compartment, mini fruit forks etc. I don't bother with the cutesy stuff for my lunches.
Some typical lunches in our house:
1/2 Sandwich, wheat thins, grapes, babybel cheese
Pita crackers with hummus, grape tomatoes and cucumber chunks, cheese cut into shapes, fruit salad
Mini meatballs in BBQ or marinara sauce, cucumbers with ranch, pasta salad
Mini tacos (from Trader Joes), salsa for dipping, baby carrots, mini granola bar
Rice, orange chicken, stirfried broccoli and carrots, sliced strawberries
Sandwich sushi - i.e. tortilla or bread spread with Laughing Cow cheese, ham/turkey and cheese, rolled tight and sliced into small pieces, wheat thins, fruit salad, grape tomatoes
Pasta salad with veggies and sliced ham or chicken, babybel cheese,
I heartily second JustBento! If you find yourself enjoying it but getting annoyed that it's taking too much time or energy to pack them, you may want to check out Maki's (of JustBento) "bento 101 course." She steps you through some of the basics of bento assembly. It focuses on the practical matters like portioning items, balancing nutrition, how to pack food safely, and planning out meals so you have a satisfying bento. Knowing these basics may help you keep the bento habit going through the times when the novelty has worn off and you are tired and busy. Also she has many pictures of "practical bento" (not fussy or cutesy ones). Boogiebaby's list is full of wonderful examples of these kinds of combos.