Well, there are actually a few things you can do...
Speaking to your Internet Service provider is a good start.
You can buy Broadband Micro Filters, which plug into your phone line line and help to clear up any unnecessary 'noise' on the line, which can (not always) make an improvement to your broadband speed.
How is your network currently setup at home? Are you using purely wireless? This can often have an effect on speeds, especially for streaming. Using Homeplugs are often a more effective way of getting access to your devices.
Let us know how things go.
