"I would love to start doing this for my kids or myself, but where do you find the time or inspiration? "
So to answer this question I am going to give a peek into my kitchen. Keep in mind that bento's are my hobby and my job, so you are not required to have quite as much bento things as I do! As I go through the tools i use, I will add an item using one of the tools to the bento boxes pictured.
First, you need a box. Below you will see a few of the boxes I use. They range from authentic Japanese bento boxes, smiley boxes from the dollar aisle at my local Rite Aid, to just plain tupperware. Also is a collection of bags and furoshiki to carry your lunch in.
After the box, really all you need is food. A good rule of thumb is is to follow this ratio: 4:3:2:1. 4 parts rice, 2 part protein/meat, 3 part veggie, and 1 part serving pickles (I usually substitute this with dessert or fruit). For rice you can substitute any carb such as bread or pasta. Don't worry about getting these ratios exact, but try to stick as close as possible to get the most healthful bang out of your box. Also try to cover these colors in your box-red or orange, green, black or purple, and white. For red/orange you can use fruit, bell peppers, carrots, or any orange veggie or fruit. Green is easy with peas, edamame, grapes, kiwi, or any green veggie. For black/purple think purple sweet potato's, eggplant, or nori/seaweed. White can be rice, pasta, or bread. Feel free to substitute brown rice!
Now to add more appeal, you can start collecting tools. Many of them are probably already in your kitchen or can be substituted with things you already have. First is the vegetable/cookie cutter. below are some in different sizes I have collected over the years and yes, I also use them for cookies. The tube like ones I ordered from Japan and are actual veggie cutters. The only reason I bothered to order them though was because I really wanted the sakura (cherry blossom) shaped one.
The next step is food picks. I have heart shaped ones, plastic Korean style picks found on holiday clearance at the grocery store, colored wood ones found on the relish aisle, and some Japanese flag style ones I picked up at Daiso on a trip to Seattle. Stick edamame, small vegies, or ham and cheese on them for some bite size cuteness. If you have small chunks of melon, they can also do duty as forks, especially the Korean style ones. Here you can see tortilla rollups held together with picks (PB and jam) and edamame on cute picks.
Then we have the dividers. For dry items, ordinary cupcake liners work. There also are nearly liquid proof liners from Japan, but you can use foil if these are not readily available. I also picked up some small metal tart pans at Cost Plus, and they work great. Plastic ramikans are also an easy to find item. There are also silicone cupcake and mini cake pans, some come in shapes, or Reynolds makes foil pans in heart and star shapes. I also have a small collection of divider strip picked up at Daiso or that came with some of my bento's. You can fake these by using scalloped scissors to cut wax paper or foil into strips. The tart pan is perfect for holding a small piece of leftover cake.
Most of my sauce bottles I ordered, though the plastic fruit containers that sugar candy cmes in also work well. Check out the camping section of stores like Walmart or Target, often they have small condiment containers that can be used for bento as well. Most of my sauce cups are also from Japan, though you can find small lidded cups in the aforementioned camping aisles, or find mini tupperware type containers. If the box isn't going to bounce a lot, wrap a ramikan in saran wrap to keep your sauce separate as well.
Then we have my collection of random tools I couldn't do without. An exacto knife and scissors for kitchen only use, and my collection of food markers that can be purchased in the baking aisle of most grocery stores. We have nori punches. Mine are actually paper punches picked up at dollar stores and dollar bins at craft stores. Also pictured is a onigiri mold. You can also use cookie cutters lined with saran wrap or your hands to form onigiri. There is an egg mold. Not a necessity but definitely cute!
I hope these idea's help you get started or hone your bento skills! The lesson here is to use what you have, that you can do this without buying lots of expensive so called authentic items.