While Google does make searching easier, it can generate a lot of the same images, just flagged from other sites.....
The other limitation I have found, particularly with clothes/ drapery, is that shots of the back half of a subject are rare...... sometimes to the point of frustration.
Classic example is how a ammo bandoleer would be attached to the back of webbing, for example.
A photo of that is usually only of interest to our niche interests.
A example of this would be Robert Jan Der Wits example of a Dutch infantry man, 1874. Robert says he's trying to determine if the shirt had a back vent....
A old manual, colour plate illustration, or a visit to a museum may generate some images, but we normally have to go in, cameras in hand.
Likewise, historical re-enactors will do the common uniforms.....
I had some books, with Osprey type illustrations (years ago) that would have been hand. alas, sold many house moves ago...
A collection of images, trawled from the net is good, however, for specific areas of interest, investing in a good reference book is advisable.
Steve, (Smeagolville) let the comments from Steve be. I believe this is a case where how the message is read may not be the tone it was intended in.
Gordy, the idea of a database is good, I would happily donate images under some sort of creative commons (where applicable) or attributed (war museums,etc) that I may trawl from the net/ database.
(humour mode) it help end the confusion on what colours to paint nipples on the occasional pin up model figure we see (humor mode off) the preceding idea may devalue the database though.....
regards
PS - Books are handy, I come from an era when "the computer crashed" was still a disaster.....if a book crashes, well, just pick it up off the floor.