On the comic I work on, my team and I come from a background of animation, so, while we have our moments of deviating from style in extreme cases, we use animation techniques to keep our work 'on model'.
Namely by creating turnarounds, expression sheets, and establishing a set style early on. When drawing, cleaning, or working on ink and paint, we're constantly referencing the model sheets we've created. Stuff like
Color guides:
Character turn arounds (nothing super formal just figuring out what they look like from different angles):
Building models for reoccurring backgrounds and props like the Razor compound
or guns!
We also double check ourselves by having our teammates go through and look for any needed revisions or inconsistencies. While we definitely notice over time our work gets better, I think that just comes with knowing we have the set limits of our style, and within those limits we can explore and play. That's why the best page of our very first action scene here:
Looks a lot weaker in comparison to one of our newest scenes here:
Additionally knowing your chocies for thematic color can REALLY help your work feel consistent too. We have direct areas of coolness, heat, saturation and hue that we've stuck to for not only different areas of our world, but also different characters, and even going as far as what colors stand for thematic elements like, 'good' and 'bad'. Using your color choices in consistency with certain thematic traits can be...frankly very fun, and pull your artwork together, without your reader really realizing it. :3
I hope this helped a bit!