Once you have gone through the advantages and disadvantages of using Flash intros and have decided that the web site cannot do without one, you need to remember several important points when creating the intro. The points are concerned with providing a pleasant experience for the visitors like providing adequate navigation and handling the control of the intro in the visitor's hands.
Because Flash intros were a way for a beginner to prove his or her ability in implementing the latest technology several basic rules were not followed. Most of these points follow from simple common sense.
Provide a "Skip" button in the intro
Make sure that you provide a "Skip" (or "Skip Intro") button from the very start so visitors who either don't want to view the intro or who are on low bandwidth net connections can quickly go to the meat of your web site. Do not test the visitor's patience by forcing them to view the flash intro in its entirety.
Provide static HTML links below or better still, above the Flash intro
Remember to provide static HTML links to the important sections/pages of the web site. This is especially important if the navigation menu in built in the Flash intro. This set of static links can be placed below the Flash but if the intro covers the entire active vertical area of the browser put the links at the top of the Flash intro.
Adding static HTML links serves two main functions -
1. Provides a option for the human visitor to jump to the page/section directly without waiting or the intro to load.
2. Helps search engine bots to index other pages/sections on the web site.
A "Loading" bar or message
If the Flash intro exceeds 50kb, make sure you put the "Loading" message. The best is to provide a "Loading" bar (a bar that expands in a defined area) or numbers as percentages with which visitors can ascertain the time left for the Flash intro to load completely. You can actually create very elegant "Loading bars" by using elements from the web site design. For instance, you can fill up a heart on a web site with a romantic theme.
If the Flash intro displays nothing till it loads fully, then it is imperative for your to have the "Loading" message or bar. If visitors don't see something in a few seconds, they will simply close the browser window or click on the Back button.
For very large Flash intros
If the file size of the Flash intro is very large, it would take a bit of time for it to load. In such cases, it's a good idea to keep the visitor involved in the page by displaying animated messages or small vector art. Remember, you have to keep the visitor engrossed in the intro if you want them to wait patiently. Do not shove in sale pitches in the preliminary messages... the best bet would be to ask intriguing questions (concerning the business of the web site, of course) so that they expect the answers when the intro loads.
Provide a link to the Flash plugin
Though the percentage of net surfers who have Flash installed on their system is more than 90%, there is no harm in providing a link to the Flash plugin download.
Music in the Flash intro
If you have music embedded in the Flash intro, be sure to put a button with which the visitors can mute the sounds. Further, if you have a good command of the ActionScript language and you have this long playing music in the intro, it would be a good idea to provide volume control.
Placing keywords for Search Engines
Make sure you place keywords of the web site in the META tags and also as plain text below the intro. Do not think that including keywords in the HTML comments will work (as most crummy SEO companies would recommend). Also, do not try to hide the text by making the text color the same as the background color. In short, do not try to spam the search engines. Search Engine bots are quite advanced nowadays and ignore or penalize spamming techniques.
Finally, make sure the Flash intro has a purpose - a reason to be there on the web site... just because it can be done, doesn't mean you have to do it.