<li>Make sure Transmission's <ahref="portforward.html">port is forwarded</a>. Port forwarding makes it easier for others to connect to you, which therefore increases your speed.
<p>If your router supports NAT-PMP, UPnP, or you have Apple AirPort, Transmission can do this automatically; just tick the checkbox in Preferences -> Network.
<li>Make sure you cap your upload speed, so that it isn't flooded. A good rule of thumb is about 60-70% of your maximum upload bandwidth. This can be adjusted in Preferences -> Bandwidth, or in real time using the Action menu.
<p>Remember, your download speed is proportional to how fast you upload. If there are many transfers running, then each transfer will only receive a small proportion of your upload bandwidth, reducing their respective download speeds.
To avoid spreading your upload too thinly, a good rule of thumb is to have at least 128 KBit/sec of upload bandwidth for every torrent you wish to run simultaneously.
<p>eg. If your upload bandwidth is 256 KBit/sec, then you should only have two (<strong>256</strong>/128 = <strong>2</strong>) downloading transfers in the queue.