When you're reading your search results, try to think of how you can improve your search to find more "good" results.
Change your keywords
Look at the titles and summaries of the results to find the keywords in your search. If some of the keywords show up in a lot of not-so-good results, you can remove them from your search.
In the "good" results, try to find new synonyms or keywords to add to your search.
Change the options in Omni
You can use the search options on the left side of Omni to change your search and find more "good" results.
Limit your search to the content types you want to find. For academic research, "Journal Article" and "Book / eBook" are usually helpful.
Choose one or two disciplines to find results that are about your research topic. Remember that different disciplines sometimes use the same words for different ideas.
If many results are out of date for your research context, limit the publication date to find information from the best time.
Change where you search
To find information in a specific content type, look at a list of databases by type. News databases are usually better than Summon at finding newspaper articles.
Search Google Scholar to find results in many subjects, like Summon. The results should be academic, but be careful to check that the information is reliable and readable.