One of the first questions I get asked as a SharePoint consultant is “how do I make my site look like Hawaiian Airlines?”. I usually answer, with a lot of money. The reality is that most people don’t understand what it takes to brand a SharePoint site. Just take a look at the Style Sheet reference created by Heather Solomon and that should keep you busy for awhile. But, if you do decide to tackle branding your site yourself (or within your talent pool at work) then here is some guidance.
Recommendation #1 – Training. Banding SharePoint requires more than just a little “Web Designer” experience. This is not for the meek or codeless designers. Just because it has “Designer†in the title, doesn’t mean that it will give your designer the tools required to brand a SharePoint site. Instead, send your designer to a basic SharePoint class first. Get them familiar with SharePoint. After they’re familiar with SharePoint in general, get them familiar with YOUR requirements. If you can find a class in your area for branding SharePoint, send them there next.  Your designer will then need some solid experience with HTML, CSS, and XML.
Recommendation #2 – Create wireframes.  Write out your specifications. Go through each possible iteration of your page to see what you’ll need to cover. If you haven’t done this yet (and it’s surprising how few actually do), you’ll be surprised at just how many pages will be involved.
Recommendation #3 – Prioritize. Find out what you really need branded. Calendars and search controls can be nasty (to brand), so perhaps a simple color change will be sufficient, rather than overhauling the whole thing. You’ll be amazed at how your “wish list” starts out and how your “needs list” ends up .
Recommendation #4 – Think about your content editors. The people contributing to the site and maintaining the customizations through the browsers may not feel comfortable with some of the more advanced Web Parts like the Content Editor Web part. If your content editors are not HTML savvy, then that might impact how you implement your customizations. It’s an easy school of thought – keep it simple.
Recommendation #5 – Plan your deployment. This is a team sport. You have to work with the Network Administrators and the developers involved. Find out how they want to deploy any customizations. Try to schedule deployments at or around the same time. Some changes require a restart of IIS while other changes can be applied without having to restart IIS.