What would be a good way to make some extra money on the side?

I'm saving up to move to the city next year for school. I haven't gotten around to applying for funding just yet, but I'm working a full time job that pays me roughly 1600 a month. I've calculated my expenses, setting aside an extra $200 for any other expenses that may come up. From there, I can still afford to save $600 per month, which would get me around 6 grand by the end of August.

I'm planning on moving into a 3 or 4 bedroom house with two of my friends, and the 6 grand would cover first month's rent and damage deposit (or at least the majority of it). My friends are also planning on saving up so we will have enough money to get by for the first month, and any money we have left over, we'll put into buying furniture and whatever else we may need for our place.

I'm wondering if there's another way I can save some more cash or make a significant amount of money in a certain amount of time. I'm not looking for anything illegal or anything that would be too exhausting to keep up with (such as having 2 jobs) but anything along the lines of figuring out some sort of formula to win money from the lottery (up to about 10 or 20 grand at the most) or making some sort of profit off of something. Any ideas?