Go for Javascript validations instead of validation controls
Use Javascript instead of VBscript.
Minimize the use of Forms authentication.
Use Connection Pooling and Object Pooling
Turn off Tracing unless until required
Turn off Session State, if not required
Disable View State of a Page if possible
Set debug=false in web.config
Avoid Response.Redirect as many places
Use the String builder to concatenate string
Avoid throwing exceptions. try to handle the exceptions without try catch.
Use Finally Method to kill resources
Avoid unnecessary round trips to the server
Use Gzip Compression
Use Page Output Caching and Proxy Servers
Use Per-Request Caching
Use Page.ISPostBack
Avoid Unnecessary Indirection
Use "ArrayLists" in place of arrays
Place StyleSheets into the Header
Put Scripts to the end of Document
Make JavaScript and CSS External
Use DataReader instead of Dataset
Make Enableviewstate property as false for the components (particularly for heavy items like datagrid, datalist etc) if it is not necessary.
Use xmlhttprequest object or scriptmanager to minimize post backs.
Declare regions for each section of codes.
Try to use datarepeater than any other data controls.
Use skins files.
