I go by mood. I tend to grab whatever strikes my fancy, and usually my mood matches the weather. On a cold day, I gravitate towards spice, pine, earthy scents. On a warm day, I usually lean towards citrus.
This is pretty much how I've done it over the past year, however, I occasionally may grab a different soap and try it for a day or two. I've found that I need to use a soap more than once in a while to get it good and hydrated and to make a consistent slick lather. Most of my soaps are soaps, not croaps or creams, so they benefit from getting wetted and staying damp. I rarely have to load any brush longer than 10 or 15 seconds anymore.
Using the same soap on a regular basis, you really get to know the characteristics of it and how to work it.
Options are good. For me though sometimes too many options are overwhelming. I also tend to find something and just stick with it, because it works and I don't think much more about it, because when I try other things I'm not sure if it really is better or not. So i sometimes miss out. Yeah it works, but the next soap could be heaven.
I have done the one til it's done. Most recently I have been doing one for a week, but today I started a 13 soap/cream rotation since I am learning straights. I will go through the rotation almost two times before I send back the Darkside Loaner Kit to @Drygulch . I actually liked the one for a week setup. I didn't have to think much about it. I would use the same soap, razor, and everything for a week and then change. I just thought I would shake things up a bit with the straights.
Well...you might say I "rotate my rotations". I have tried several different approaches to working my way through 25+ soaps...I use one method for a while, get bored and then switch up to another kind of rotation. Right now I have selected 14 (the others are in a box in the closet) and I work through them in alphabetical order. If you post this same question in a month or so I can provide you with a different answer.
I just look at my collection and pick something that sounds good. I try to use everything and if I see something that hasn't had some love in a while, it moves up on the selection list. Basically, it is whatever I feel like. New additions get used usually the next day until all are tried. Steve
For a few weeks now, I've been doing one shave soap(or cream)and A.S. every 4 days. Thing is, since my den has increased, I find at the end of the 3rd day that I can't wait to finish the next day's shave, so I can move to the next set. Maybe I'll do it every 3 days, see how that is. I have 3 soaps and one cream.
Mood! Its all about the mood - any other process is just too hard. I have around 30 soaps now and about 15 are standing in the door (Airborne term) on any given day. If I had better/more storage I would have all the soaps out and standing in the door.
Often, actually always until recently, it's been a mood thing for me. But in the end I got so sick of "having" to pick one each day that I instilled a new system. When I load a new blade, I choose a soap/cream and brush to go along for the lifespan of the blade. Then I choose a new soap/cream/brush when I install a new blade. This way I get to acclimate to a product, find it's weaknesses/strengths and having a calm mind. Works for me Yeah, this. Sounds like what I'm doing as well. A blade normally lasts 6 shaves for me, so a week give or take.
Mainly by mood, and secondarily by season. I actually look forward to picking out what I'm going to shave with the next day and laying it all out the night before. Variety is the spice of life...
For me, it's about scent/menthol. A menthol soap is for me almost always a summer-soap. Winter soaps for me are dark and warm scents, whereas summer soaps are light, frisky and maybe fruity. Add menthol and you have a winner soap for the summer
Sunday - Citrus Monday - Menthol or Mint Tuesday - Tobacco Rest of the week depends on what I feel like using.
For now I'm using the same soap 5 days a week (for the month) and choosing something different for the other days. Started this in January and continuing now, but not sure how long I'll go at it like this.
HOOAH! I have the original LP of "Blood Upon the Risers". Went to jump school at Ft Benning back in '71. Followed by the Q Course at Ft Bragg and my first tour with the 5th SFG. Listening to this has me thinking about all those wonderful days.