Some months ago there was a discussion regarding above and a link to a video where the provider showed a very inefficient manner of doing so as well as being, in my opinion, much less safe than the alternate I suggested. The particular point in contention was the coping of the end for muntins and the order in which operations were done, the video treating every piece individually whereas I commented on cutting to length a block of material, coping, _then_ ripping to width and sticking...
At the time I mentioned that Delta/Rockwell in the ages of their heyday had published a very nice technical document on same but that unfortunately over the years my copy had gotten so worn it wasn't legible when copied. While looking for something else, I just happened to have stumbled over the tract at OWWM in its entirety in PDF form so thought I'd share the link. The particular operations are described therein as the following --
SASH BARS AND MUNTINS. Very frequently, the sash, especially
> the upper one, is divided into a number of smaller lights.
> Vertical uprights which separate the panes of glass are called
> sash bars, while the shorter horizontal strips are called muntins.
> All of the light wood inside a sash is often referred
> to as muntins or munts. The manner of fitting sash
> bars and muntins is shown at the top of Fig. 24. The necessary
> marking and cutting of the mortises in the main frame
> would be made at the same time as other previous operations.
> The muntins are 1% in. thick to match the thickness of the
> sash, but vary somewhat in width, being narrower where the
> sash has many lights. Approximate average dimensions
> are given in the drawing and will be found suitable for most
> work. The stock for all of the sash bars necessary should
> be in block form. In this shape, it is cut to exact length
> and coped at the end which is to fit to the top rail. The end
> which fits to the check rail is simply square-cut to the tenon
> dimensions shown. After this cutting to length, the wood
> stock is ripped into pieces of the required width. Each piece
> is then stuck on both sides with the same set-up as used for
> the main frame.
> Muntins are made in the same manner as sash bars, with
> the exception that the tenons are flush with the ends, as can
> be seen in the circle inset, Fig. 24. Mortises to receive the
> munts are thus the same depth as the glass rabbet, or % in.
> The joint between muntin and sash bar is the same as muntin
> to stile, as shown in the detail drawing joint at "A." The
> wood stock should be cope-cut in block form before being
> ripped to width for sticking.
Hopefully somebody here or in the future will find this instructive.
With the demise of shop instruction of any depth in HS, finding these kinds of detailed "how-to's" for the practical operations is increasingly difficult and consequently most self-taught individuals either have to reinvent the wheel and stumble upon the proper sequence and specific operations or, like the poster of the video referred to, use far inferior techniques not knowing any better.