* Cascading Style Sheets
Cascading style sheets provide a greater degree of control over site design by keeping layout and content separate. A well-designed CSS also speeds up site loading time. Visit this site for an in-depth look at how to construct and use a CSS properly.
Current best practices dictate that the use of the TABLE tags are replaced with CSS table substitutes.
Although the concern is generally unwarranted, many people have turned cookie acceptance off on their browsers. IE ships with a highly-restrictive cookie acceptance policy as its default.
Consider avoiding cookie use altogether and never require the acceptance of cookies in order to view any portion of a web site. If cookies are being contemplated to track login status, consider using SESSION ID's or other appropriate cookie alternatives.
If you do use SESSION tracking, NEVER hard code a SESSION ID into any link. Doing so can compromise the site's security or the security of an individual user. The most common way that SESSION IDs get encoded into links accidentally is when the developer copies and pastes a link from their own browser that is already displaying a SESSION ID.
Keep in mind that these best practices represent the minimum quality standards that we want to code to. Remember, when in doubt; choose what's best for the user who is visiting the site with the lowest level of available technology.