Some general guidelines for brewing lagers as outlined by Palmer in "How to Brew"

• Pitch yeast at lager yeast temperatures 50-55°F (should see activity within 24 hours). It may be necessary to pitch a higher yeast count and fermentation is slower and less vigorous with the lower temperature.
• When airlock bubbling slows down, perform a Diacetyl rest (3-5 days after pitching yeast) by raising the temperature by 10-15°F at a rate of no more than 10°F per day.
• Keep at this higher temperature 4-7 days (could go as long as 2 weeks).
• Lager - reduce temperature by not more than 10°F a day down to 35°F. Lager for 2-4 weeks, Palmer recommends shorter 1-2 weeks if bottling but most lagering sources suggest 4 weeks.

Some other lagering tips provided by Steve Holle of KC Bier Company in Kansas City for brewing traditional German-style lagers in the Jun-July 2020 Craft Beer and Brewing include:

• KC Bier uses 100 percent imported malt and hops from Germany and yeast from a Bavarian monastery to produce authentic German flavor.
• They also use a traditional three-temperature step mash, with at least one of the steps accomplished by decoction.
• Lager yeasts should be pitched with cell counts 50 to 100 percent higher than warm-fermented ales since reduced metabolic activity dampens yeast's growth rate and slows fermentation time. KC Bier knockout at 46°F and pitch 1.5 million-plus yeast cells per milliliter of wort and let temperature free rise to 50°F.
• At the end of fermentation, some lager brewers may allow the temperature to increase to 59°F or higher to reduce diacetyl or bolster attenuation. Because the potential for yeast to produce esters is lessened after fermentation, there are few, if any, adverse flavor effects from a diacetyl rest.
• After fermentation a good practice is to lower the temperature slowly by a few degrees 2-3°F per day to a final temperature of 32-35°F rather than cold crashing.

Some other traditional lagering rules of thumb provided by Drew Beechum in the Jun-July 2020 Craft Beer and Brewing include:

• Grow twice as much yeast as you would for an ale.
• Chill the beer to at/below pitching temperature, 48-50°F.
• Pitch the yeast and wait 24-48 hours for fermentation to begin.
• Maintain the temperature for two weeks and watch minimal krausen form.
• After active fermentation slows, raise the temperature over several days to 65°F. Allow the beer to sit there for two or three days to clean up the diacetyl.
• Lower the temperature 1-2°F per day until just above freezing.
• Allow the beer to "lager" just above freezing for four weeks before packaging, then keep cool until properly carbonated.