Hi Astc,
Some of this is specific to the type of timber framing you are doing. I would also note, within the realm of the craft, there is much diversity. You very well may get a number of variable answers to this question.
Should I plan on drawboring every mortise and tenon joint?
Short tenons, like on braces do not require draw boring and in general, braces only work in compression and don't even need to be pegged if the frame is cut well. Braces do respond to wedging in some styles.
Is there and order which you should do it?
This could depend on style and system of raising so is hard to give a definitive answer.
For instance can you drawbore the braces as well as the plates and crossbeams or would you do one and not the other?
You do not draw bore braces, there is not enough relish in the tenon.
Also, what pegs should be used when drawboring?
Dry hard wood is typical (and probably the best) but there is plenty of heart pine, and other conifer as well found in vintage frames and other styles.
Tapered, chamfered, octagonal?
Tapered is about the only "yes" to this answer but the rest is subjective.
And what pegs should you use when not drawboring.
I don't think I am understanding this question? The pegs down change whether you draw bore or not.
Hope this helped.
