Directly from alpha blogger "Takky Mama"
Basic of BENTO

How to Fill Bento Box Beautifully

Putting warm-remained dishes into Bento box causes damage to the food. Put them after cooling.
Strain off the water firmly from the raw vegetables, which are for color variation. Use the partition to prevent the food from sticking to each other. Remove leaves of cherry tomatoes etc, to avoid various germs.
Avoid watery vegetables as possible as you can. Coating watery dishes with ground sesame, dried bonito shavings,or tangle flakes takes up its moisture. They also add flavor to dishes, please give it a try.

Time Reduction Techniques for Bento

Choosing dishes that can only be cooked with microwave oven and toaster leads to reduction of cooking time.
Bento in the picture is a super time-reduced bento, where you can heat three dishes with a microwave oven all at once! Wrap two kinds of cut vegetables separately. Wrap and marinate the pork with "Yamasa Sukiyaki Sauce." Finally, put the three dishes into the heat-resistant container, and heat it for four minutes.
After heating the side dishes, season the asparagus with namul-like flavor, and season shimeji mushrooms with "Yamasa Kombu Ponzu" with dried bonito on top.
Once you prepare cut vegetables and rubbed porks in the wrap the day before, you just need only four minutes to finish the super time-reduced bento in the next morning.

Remake Dishes

Some people reuse last day's leftover dishes for Bento, and some get depressed by that.
Contrive leftover dishes while you rewarm them in the morning. Leftovers will change into totally different dishes and you can make full use of them.
As they are once cooked, they are well done and taste good. Because of such reasons, it is appealing to remake dishes, not to cook from the very beginning.