I'm new to DE shaving, having just started a couple of weeks ago. Things have been going pretty good for me, and I feel I'm quickly coming up the learning curve (thanks to B&B!). One thing, though, has been a source of frustration, and that is lather building.
I fell into the habit of face lathering on my second shave. I love face lathering because it feels like I'm massaging my face. Very relaxing. However, from the beginning, it's always seemed like I'm not getting enough lather. I've tweaked my methods by starting off with a wetter brush, then a dryer brush, soaking the soap, putting a bit of water on the soap, starting with a dry puck, and so on...but I never been 100% satisfied with the result. I'd get just barely enough for 3 passes, but I'd have to squeeze the brush for that third pass.
Tonight as I was finishing up my shave it it finally clicked. After each pass, my face was pretty dry. Up until that point, my efforts to increase lather volume have been to try to load more soap onto the brush, not on experimenting with the amount of water being used. After cleaning up I decided to whip up another batch of lather in my apothecary mug and keep adding water until it negatively affected the lather. Below is a picture of the result.
I soaked my brush, squeezed it, made 40 slow swirls in the jar of Tabac, then started to build the lather in my mug. I added a bit of water every so often, whipping it in as I went. I wish I had kept track of how much water I used, because it was quite a bit more than I expected I could. The photo below shows the volume of lather I ended up with. Well, most of it anyway, I lost some of it as the mug started overflowing. If you look closely, you can see my brush, almost covered in foam.