A common situation when you are doing a search is that you get too many results. Remember, a good search result list shouldn't contain more results than what is possible for you too look through, at least superficially. Provided that you have done a good search and that the results are about the subject you are interested in, there are a few things you can do to limit the result list.
Perhaps you have chosen a subject where not much research has been done. One option then is that you choose to focus on for example one species, one nature type or a certain process in your assignment. You can still include background information about the bigger picture, but if you do your search a little more specific you run less of a risk being overwhelmed by the amount of results. Perhaps it is even suitable that you change your research question to something more narrow, but that is up to you.
To make your search more specific, you can include more search terms, not synonyms, but more concepts. You can also choose more specific and detailed search terms.
In most search tools you can select that one or several of your search words must be present in the title. This way you can quickly sort out the publications that are specifically about your subject, not just one of serveral things that the publication addresses. Often you choose to search in the title in a drop-down menu next to the search box.
Using filters after you have done a search will reduce the number of results and sort out those that are most interesting to you. Filters are commonly found in the left-hand menu. You can for example limit the result list to only show new publications, or only review articles. A new review article is an excellent starting point to get an overview of a new subject!
There are often many ways to sort the search result list, for example according to date, relevance or number of citations. The default one is often different between search tools!
To sort the result list will not reduce its size, but it can be a quick way to see whether you have done a good search, and also to find the most interesting publications.