What about the “Upside LVs”? People e-mail me the whole time. Some styles of authentic Louis Vuitton designer handbag will have “upside down” LVs on the back. The reason for this is that Louis Vuitton uses one continuous piece of leather that runs roughly from the front to back, without a seam on the bottom-and yes, the rear has inverted logos. This applies to the Speedy, Papillons, Keepalls, and some similar styles. Most monogram pieces (each piece with a piece of cloth or leather on the bottom), the LVs right up on both sides.

What about the patches? It is true that many older fake Louis Vuitton designer handbag had patches on the inner and outer that simply never been on authentic versions.
But, some authentic designer handbag have them! This is particularly true for vintage Louis Vuitton designer handbag where there is a round patch intended for personal relief. 
Some current designer handbag have also patches within, like the Viva Cite.

The Fonts: designer handbag Louis Vuitton uses a very unique font. I’ve noticed that a few have begun to knockoff with fake Louis Vuitton. Be cautious, therefore, but the current Louis Vuitton all fonts will look like a patch. Note the VERY rounding “O”s, for example.