Good Will Hunting : Tweleve Performance Tips

This is an extract from MSDN article.

Twelve Performance tips

• Load fewer modules at startup
• Precompile assemblies using NGen
• Place strong-named assemblies in the GAC
• Avoid base address collisions
• Avoid blocking on the UI thread
• Perform lazy processing
• Populate controls more quickly
• Exercise more control over data binding
• Reduce repainting
• Use double buffering
• Manage memory usage
• Use reflection wisely

You can read the article at
http://msdn.microsoft.com/msdnmag/issues/06/03/WindowsFormsPerformance/default.aspx#Tips

Lot of information available in it. Check it out for sure.