Regular eating schedule. I am currently trying to gain weight as well: with a B.M.I of 12 I am severely underweight and have an aim to gain 21KG before I am considered a healthy weight. As I just mentioned: REGULAR eating schedule; even if it is just a small bowl of cereal in the morning, eat it, if you can't manage big meals, like myself, just have a 5 meal schedule such as:
> Morning: Small Breakfast
> Prior to noon: Brunch! Make a hearty meal out of this.
> Mid-day: LUNCH TIME! If nothing hearty go for something that feels filling and is substantial.
> Evening: This meal is just as important, remember to have a larger meal around now, you'll feel awake enough to do so.
> Night: A bit before you go off to sleep, have something small but hearty - ranging from crackers to a bowl of soup or even just a buttered slice of bread or two.
Of course you could change what meal is where, try make a variety of foods including a snack of fruit or something (satsumas., bananas, apples and etc) or sometimes switch the breakfast meal to a bacon sarnie or something a but bigger than usual but never forget or leave out a meal as it will take you out of sync and make you want to eat less. As you're still in school and all, use the breaks effectively to eat a little bit if you can't get a substantial meal for that time, but remember that if one meal is slightly smaller than usual, another meal should increase in size to balance out the food loss of the prior meal. Overall, keep it regular and keep it filling.
IMPORTANT: Drink lots of water and occasionally juice, as dehydration can make it harder to be motivated to eat: orange juice is a good supplement to a schedule like this in some of your meals but don't go over the top as it can give you the shits.
Good luck -Joey.