Tips and tricks for photos on a photo sharing site requires that you think creatively of keywords that describe exactly what you want. Searching photo sharing websites is dependent upon what your objective for finding the photo is. There are a wide range of reasons for finding photos on photo sharing websites. People use the general Google search (not "Images" search) to find photos from anything to getting a good laugh to defining words with which they are not familiar and from seeking out free use photos to purchasing a photo on a photo sharing website. Generally, searching Google "Images" is not a good idea because it sometimes yields inappropriate results. The ease with which you are going to find photos on a photo sharing website is dependent on the complexity of the keywords and the number of photos on the photosharing site.
Consider a person looking to buy a camera. He has two choices for searching a photo sharing site – searching Google indirectly or directly searching the site.
Generally it is easer to find camers by category if you type "cameras Flickr" into Google. Google conveniently sorts out the cameras by brand in the first entry of its listing under "Flickr Camera Finder." Continue navigating the Flickr site and you are shown images taken by Flickr users by the type of camera with which they have shot. When you type the keyword "cameras" into Flickr directly you get a stash of camera images helter-skelter on the page that is hard to navigate, much less find images taken with a camera that you are looking to buy.
If you search for images of horses indirectly using the general Google search (not "Images" search), you'll most likely get the horses (all types) group as the first listing. Not bad for an indirect search. Search for the keyword "horses" in Flickr and you'll get rows upon rows of images of horses. Even when you click on the "Groups" link, you'll have trouble finding a general page of images of horses.
Imagine that two people are in a conversation in a cafe and one lets the other know of some humorous photos of smoking men that he saw on Flickr. The other person is going to want to find those pictures on Flickr. The easiest way is to type in "Flickr smoking men" without quotes into Google. You'll get links to smoking men photos and groups such as "Men Smoking Pipes."
A more efficient way to search for a men smoking group is to go directly to Flickr. When you type "men smoking" into the search bar on the Home Page, you'll be taken to a page filled with photos of smoking men. More importantly, if you look at the banner links at the top of the page, you'll see three choices: Photos, Groups and People. If you click on "Groups," you'll get an extensive list of groups that contain pictures of men smoking.
Finally, esoteric keywords such as "smoking men" are only available by searching using the general Google search (not "Images" search) or directly on Flickr as described above. Sites such as Picasa Web Albums, Photobucket and SmugMug don't have many photos of smoking men so that when you try to search for those keywords either indirectly on Google or directly on the website itself, you won't get many images of smoking men.
After researching the search opportunities for various photo sharing sites, you can come to some conjectures about the process. One of those conjectures is that searching Google indirectly by using the "keyword" "name of photo sharing site" as keywords. Google seems to do better at organizing its listings of images than any of the photo sharing sites do.
Finally, note that Flickr has the most images of any photo sharing site. Searching photo sites like Photobucket and SmugMug doesn't get very good results either indirectly through Google or directly through the photo sharing site.
Photo credit: Maggie Smith https://www.freedigitalphotos.net/images/view_photog.php?photogid=172.
Author's own experience.