So im currently downloading a game and was quite upset that I was maxing out at 500Kb/s
A few google searches later, I found a way to increase my download speed.
As of now im running at about 1.2Mb/s.
Please note that the following steps are done on Mac, but the steps are the same for Windows.
Step One(Mac): Open up your Steam preferences, this is done by by clicking on Steam on the top left, and then clicking Preferences.
Step One(Windows): Open up your Steam preferences, this is done by going to File>Preferences.
Step Two: Go to the "Downloads + Cloud" tab.
Step Three: In the Downloads tab you will see two pull down thingys, set them like this, but change your download region to the city nearest to you.

What this does: Changing your Internet Connection to Cable/Fiber > 10M raises the download cap, and Changing your Download Region just makes the place your downloading it from closer to you.
Hope I helped, if I didnt, im sorry.