I post twice a week. I am able to do that because I had a buffer of 52 pages when I started (which is now down to around 48-49 pages), and because I am able to draw two new pages a week. Not everyone is in that position, and that's okay.
I don't really cut any corners - I just plan ahead a lot, take breaks between chapters, and have worked on this comic long enough that I've found a routine that works for me. I mean, I don't do full-blown paint-everything-in-incredible-detail when I draw comics - there are some things I've simplified - but I wouldn't call that "cutting corners".
It depends on the page - simpler pages with fewer panels are faster, complex pages with lots of detail are slower - but I average somewhere around 7-9 hours per page for just the drawing. A simple page can take me 4 hours, a complex page can take me 12 hours.
... Which doesn't count the time I spend outlining, prepping, thumbnailing and planning.
Advice to someone looking to increase speed: plan ahead. Know what the next page is going to look like before you sit down to draw it (i.e: do thumbnails of your page-layouts). Do concept art - if there's an important setting or architectural detail, do a quick sketch of it beforehand so you know what it will look like; draw turnarounds of your characters so you know how they look from all angles; if there are important symbols or flags or whatever in your comic, design those before they show up on the page. If you work in colour, do colour-keys for the different scenes - i.e: a quick colour-sketch of the setting for the scene, so you know what kind of colours you'll be working with (warm sunlight, blue nighttime scenes, yellow-purple for desert scenes, etc., etc.) and you won't have to start from scratch on every page.
Learn useful shortcuts in whatever software you're using. Set up actions or memorise hotkeys for certain functions, and don't be afraid to use them.
Figure out how you work best; what method do you need to use to stay focused on your comic-work? I need to listen to podcasts during the sketching/inking/colouring rather than music, because podcasts keep me focused for longer periods of time. I need a cup of tea and perhaps a snack to keep me from getting up and wandering off in search of either. But you might need a different setup - maybe you prefer to work with music in your earphones! Maybe you prefer silence. Maybe you work best in the mornings, or best in the evenings.
And most of all - don't feel guilty about not managing to update more often. 99% of us are doing out comics entirely for free, in our spare time, and it's okay to only update as often as you can comfortably manage. Pick a schedule that suits you. <3