Steve Morse helped many of us when he created his One-Step Tools for the Ellis Island website and for many other databases. You can find them at stevemorse.org. These search tools allow you to enter various search criteria and hit a search button only once. This lets you narrow down your search but can also complicate matters...the more information you enter, the less likely you are to find the person you are looking for if there are inconsistencies in the data or transcription errors.
As with all searches, I recommend started with exact data because you may get lucky and find your person right off the bat. If that doesn't work, try different variations with the data. If you're researching a common surname, use the "year of arrival" to search one year at a time. You can even search using first initial only.
In some cases, you'll find several results for the same person. This has happened to me serveral times. The passenger lists are created at the time a ticket is purchased. If the passenger doesn't make the voyage, a line is drawn through that line. The information can still be useful if it is legible so it's still worth keeping.
As with all searches, if you can't find the person you're looking for, step back from the search and start fresh after a period of time. You find find more information that will help your search. Also, don't assume that his apparently more sophisticated search tool is better than the Ellis Island search engine. Sometimes the simple search engine is better. I'd been trying for years to find the manifest for my ggm Lena Belinsky (Lea Belinki) using the Steve Morse tools and the ancestry.com search engine with no luck. This summer, my cousin tried a search on the Ellis Island site and found it in 2 seconds. I wanted to kick myself for not trying it sooner.