Check the publication date of the photos
Fake profiles often have a "suspicious" feed: either there are many photos all uploaded within a few days or there aren't any or there are only a couple. Normally the uploading of the same is a couple of days away with the aim of "filling" the feed and therefore giving a semblance of constant updating, which is why it is important to check when they have been added to the profile. If, on the other hand, they are managed by real people, it may be that the upload is done in a smarter way, but it is easy for them to be - for example - dozens and dozens of photos all of sunsets, or parrots or in any case of subjects easily available online.
Incomplete profile information
Followers list: who follows and who is followed by
The list of followers and people followed is another aspect to take into consideration: if the followers are all profiles without photos and/or of Indians/Arabs, it is very likely that it is a fake (and/or a profile that has bought followers). Ditto the following list: if they are all famous people and / or people with suspicious accounts, it is almost certain that it is in turn a fake profile.
Link and photo dared
Comments under the other posts
Comments under other users' posts are also a way to identify bot profiles: just - for example - go to any profile of a Serie A football team to notice a slew of risqué fake account comments.
If a profile is suspicious but seems managed by a real person, you could try searching Google Images for one of the uploaded photos (especially the one used as an avatar): if you find it on Google and it belongs to another person, then the user question is refreshing the page looking for clicks on the web.
