Embase offers you basic and advanced methods for searching, as well as specialized search interfaces for things like the PICO framework. As seen in the image below the fastest way to get started is just typing your keywords into the search box. You can type terms separated by spaces (Boolean search terms like AND/OR/NOT are optional). Note that as you type, Embase suggests subject terms (from Emtree) that you can use to search though these are optional. When you search with basic keywords Embase (like with PubMed and MeSH) can usually match your keywords to Emtree terms.
One nice feature about Embase is that it will show you the number of results before you click search. If you see that you are getting too many or too few results, you can amend your search before running it. The small pencil image to the right of the search box allows you to limit your search to specific fields like title, author, or abstract. The plus sign below the search box offers more search space including "all fields" that can be linked to your other search terms by Boolean operators (AND/OR/NOT).