1. Field length: Be aware of Database field length for corresponding UI fields. For text fields and text boxes, length must be smaller than Database field length (about 10 characters smaller for every 100 char in db). This is needed for dealing with multi-byte character set.
2. Blank space: No space before 'colon' and 'comma' - use space after comma.
3. Date: Proper formatting of date
4. Access Control/Privilege Checking: For important business information which depends on user privilege, make sure, list that user sees, are based on their access privileges
5. SQL injection: Use bind variables to avoid SQL injection
6. Double submission problems: What happens when user re-submit the request - handle properly.
