Which way do you go?
I've taught my Glove 101 class several times in recent months. It targets intermediate knitters who are beginners at knitting gloves. To teach as many skills as possible, students work through a sampler that gives them the opportunity to build a series of skills. I always get at least one student who tells me I have reversed the increases on the thumb gusset.
Increases exist to shape the knitting, making it larger or smaller. There are a number of different techniques for increasing. All are visible to the discerning eye but some are more obvious than others. Yarn overs can be used as a decorative increase, for example on a top down raglan. We normally work increases on the right (public) side of the knitting to have more control over the outcome.
In class we work the glove in stocking stitch using a M1R increase on the left and M1L on the right. I've looked at a lot of glove patterns to check what increase is recommended. Many patterns avoid the issue of which increase to use by giving the instruction as inc 1 with no specifics as to the intended increase. I see M1L and M1R (in that order) fairly frequently and on occasion I see them in reverse order.
The same issue comes up regarding sleeve increases. Most patterns leave the increase method to be used up to the individual knitter. What we are really asking you to decide is do you want the increase to slant in the direction of the increase in the work or do you want the slant to be towards the centre of the work. Some knitters are totally unconcerned by this distinction and use the same increase on both sides. I myself prefer paired, symmetrical increases.
However, there are no knitting police. I think knitting should be about pleasing the knitter so the choice is up to the individual. Whatever decision you make I do recommend that you be consistent within a single project. I further recommend that you practice as many versions as possible so you will always have an alternative method in your repertoire should you be unhappy with the results of a particular method.
To see increase video tutorial from knittinghelp.com go here. It includes a variety of methods that you can practice.