Some tips from me :)

1- Water -

Since it's Winter, we don't drink as much water as we do in the Summer. We tend to forget because we don't feel we should, or thirsty. But a fact is, drinking water is very important, in both Summer and Winter. So what I do is I always keep a glass or a bottle of water next to me everywhere I sit in the house. Like when I am watching TV, studying or working on my laptop, it's there next to me. I see it, so I drink it. I don't wait until I get really thirsty to drink. And that's the best way.

So my tip is; KEEP THE WATER NEXT TO YOU.

2- Aerobics -

Sometimes we are too busy and we don't have the time to go to a Gym. We are occupied with work and studies that we feel are more important than body training. But, it is not healthy for our body and muscles not to move for several hours a day. I, for instance, love to work out. I love to go to the gym. But during exams I stay home and study, and leave it for a while. But I know how important it is for our bodies. So what I do is I take a break from what I am doing, - especially if it's sitting for many hours- I start stretching with some aerobic exercise. This does not take time. If I am very stressed with my studies, I do it for about 15 minutes. That way I am not wasting a lot of time by leaving to a gym and yet keeping things under control. 

Following a regular aerobics program gives a sense of commitment and control - two positive mental attitudes that help counteract stress. Aerobics also relax tense muscles, thereby relieving you body's stress response.

Or, if not that, something else I do is dance! I love dancing. So I just put on some music I like, good songs, hits, and dance. Using all kinds of moves in the dance. Like crazy people dance. That way too is some kind of exercise for the body and muscles.
So my tip is; TAKE SHORT BREAKS FOR DANCING.

3- Sleeping -

Sleeping is also important. But sometimes less hours of sleep are also good and enough for our bodies. Taking control of our sleeping hours is very good and important. 

Because why to waste the time sleeping when you don't need it, instead of doing something else in that time?
So try to SLEEP LESS HOURS, as much as you feel you can. And always try to keep it as a routine, because then your body get used to that much of sleep and you won't be tired or feeling the need of sleeping more. That's what I do. I sleep approximately 6 hours a day (if on a holiday I sleep about 6 to 8 hours).
So that way I get the amount of sleep my body needs, and the rest of the day I manage to do so many other things.