Flat glass tinting is much easier than auto glass tinting.
The most important thing to remember is that large windows (over 15 square feet or so) are subject to thermal fracture if too dark of a window film is applied. Be sure to use semi reflective residential window film.
The most difficult part of residential glass tinting, is removing the clear liner from the window film just before its applied to the wet glass. On smaller panes one person can hold the film as another pulls the liner off, or with practice you can hold one corner in your teeth and pull the liner off with your free hand.
Reversing the liner to unroll and peel
An exaggerated cross section of a reverse peel
On larger panes you will need to roll the window film onto a pvc pipe (about the same lenth as the width of the glass to be tinted).
Roll the oversize piece of window film (1 inch larger than the pane all around) onto the pvc pipe with the liner side up, moisten the final foot or so, peel the window film from the liner about 6" as you spray soapy water (10 drops joy dishsoap or ~20 drops of Johnsons Baby shampoo per pint) onto the exposed adhesive, lay the liner back onto the roll and peel back the film (like separating two layer toilet tissue until it wraps all the way back around).
Hold the window film so that you have hold of both corners so that when you let go of the roll it will un roll and peel the liner for you, then you just carefully place it onto the prepared window.
Spray the window again, wipe the edges along the sides and top in one stroke with a clean heavy duty paper towel, then squeegee dry. Spray soapy water liberally onto glass, avoiding the top inch of the window to prevent dirt from bleeding down. Flush the edges to get rid of loose paint chips and dirt. Peel the liner with a helper or the roller and lay it onto the soapy wet glass.
If you used the roller, the clear liner should now be against the window film, just carefully lift it off and discard. Spray soapy water onto the window film you just laid against the wet glass and squeegee it out from the top down and the center out. Dont squeegee all the way to the edges, stop short about an inch. Get a credit card or similar hard card and a snap off knife, trim the excess window film by placing the card into an edge, placing the knife against the card and drag them both along the edge.
Wet the window again, this time squeegee firmly all the way to the edges. Blot excess water from the edges with a card wrapped with a paper towel to prevent the water from creeping back under the window film. This will get easier with practice, try smaller panes first, dont get upset if you ruin some tint, it's the only way to learn.