Hello Mandi-
For Agencies, there are two typical ways to get started creating a new website for your client.
You can start with BoldGrid Inspirations, which will let you select from a variety of industries and themes for those industries.
Alternatively, you can start with our WordPress SuperTheme BoldGrid Crio which will give your team an advanced WordPress design suite with controls for every aspect of your client’s new website design.
For your question regarding Leveraging Browser Cache, we use several scripts on our marketing website that require frequent updates, so we have shorter cache control headers set for some of those. Leveraging browser cache is a great way to speed up your website, but sometimes you may have assets on your website that you don’t want to have cached for long periods of time. You can control your cache control headers with a plugin such as W3 Super Cache to configure your cache control headers for your site’s needs.
I hope this helps!