1.
Tip: Purge the Downloads Queue!
2. Close all tab windows you don't need open at that time.
3. Clear searches if they're getting oldish. They go stale after a while anyway as people come & go online.
4. Disable Ultrapeer capabilities under the Speed settings in LW prefs.
5. Keep your Shares below 2,000
6. Keep LW hidden in the dock rather than in the background.
7. If LW is starting to slow the system, close it & re-open it.