Choosing the right theme for you is important
Though WordPress has made it easy to change themes, that doesn’t necessarily mean things will work the same. Something as simple as the size of your videos in one theme, could mean that all of your videos don’t fit in the content area on the new theme. It is a good idea to know what you want your site to be prior to choosing a theme.
For some things like a video site or an eCommerce style website, there are themes which have been designed specifically to meet the special needs of your site. Choosing a theme that has your needs in mind can not only make the site easier to set-up, but may also make the ongoing maintenance of your WordPress based website much easier.
The great news is there are companies like StudioPress that make incredible themes for reasonable prices, that you can use to have the website you always dreamed of.