Here's how I usually approach the issue:
I first load to the book-recommended OAL, measuring from the cartridge base to tip of bullet. I check the first round to see if it fits in the magazine, then feeds, chambers and extracts freely. If so, proceed at that length. If not, adjust shorter so that the loaded round DOES feed and chamber. Ideally, I like to have the bullet base even with or above the base of the neck, if that corresponds to the book OAL.
After I find the best powder and charge for that bullet at that length, I'll slowly seat it deeper to see if there's a best or better seating depth for accuracy. I'll use increments of one-half turn on the standard threaded seating stem, or .005" with a micrometer style.
Once I find the best seating depth, I use a caliper to mark a bullet at bore (not groove) diameter - .300" for a .30-caliber, for example. I measure the distance from that line to the cartridge base, and record the number.
If I change bullets, I score one the same way and set its seating depth to the recorded number. That gives me the probable best seating depth for the new bullet, without experimenting.
Note: at NO time did I ever measure, know or care about "distance to lands." Don't need to - ever.
Here's a round, marked at bore diameter, as described.