1. Find a box.
You can look for cute boxes on eBay, or if you live in an area with a strong Asian community, can probably source them locally. If you’re not able to do that, any Tupperware-style box will do. Glad, Ziploc, and Rubbermaid all have semi-disposable containers too. Pick one that is not too deep, for versatility. I have examples of not-remotely-bento boxes on my blog, to show that it can be done!
If you choose to go the eBay route, pay attention to the capacity of the box. 600mL or so is a good size to get started. Bento snack boxes can be very small, so read the listing so you know what to expect.
2. Think in thirds when filling the box.
I try and aim for a balance between carbs, protein, and veggies (sometimes fruit, but I try and go for more veggies). You will probably be able to see this balance in action in most of my bentos on the site. Traditional Japanese bento is usually 1/2 rice, but I try and go for 1/3 most of the time.
3. Use what you have on hand.
There are many, many beautiful bento blogs out there featuring all sorts of fantastic food, but my fiscal reality, as well as my living rurally, impact my choices greatly. I would like to say I eat locally all the time, but it’s not always possible.
I’m vegetarian, but my husband is not. I generally prepare the carb and veggie portions of the bentos together, then the protein part separately. I like eggs, tofu, faux meats, and cheese for the majority of my protein choices. My husband likes ham, and I find that a rotisserie chicken is a great option – for bentos as well as for him to snack on.
I am a big believer in using leftovers, as it cuts down time in the kitchen, uses what’s on hand, and is generally more financially responsible. Maybe it’s because I really hate wasting food? Burgers for dinner? Make one up with a cooled patty, cut it in halves or quarters, and place it into your bento. Meatloaf (or veggie equivalents) makes great sandwiches. Chili is usually better the next day… repurpose what you made for dinner.
With veggies, I generally get what I like, what looks fresh, and is at a good price. If you don’t like it, you probably won’t eat it, right? The great thing about bento is that I consume more vegetables through the day than previously, when I’d pack a sandwich and a piece of fruit (I like to base bentos around sandwiches, as they’re tasty, so bear that in mind).
4. Stuck for inspiration?
If it’s just something quick, google image search is your friend. For ongoing inspiration, there are a great number of blogs out there, on both the wordpress and blogspot hosting services. I can still let an afternoon drift away on me by looking at pictures of other bentoists’ creativity.