The easiest way is to ask good shooters what they use and start there. That's what I have done, simply let others do all the leg work and copy.
I will get a bullet and powder recommendation and use the bullet weight, adjust the powder charge, and see what happens along the way. The 30-06 is easy, it has been around since 1906, there are a number of combinations that are staples. Powder staples are IMR 4895, IMR 4064, and IMR 4350. For a M1 Garand, it is hard to beat a 168 SMK with 47.0 grains IMR 4895.
I have been shooting outstanding groups with that combination out to 600 yards, in gas guns and bolt guns, for decades now. A very popular load for bolt gunners was a 168 SMK with 55.0 grains IMR 4350. Recently I have been developing loads with 150 grain Fusion pulled bullets. I copied some loads. A lot of shooters use 59.0 grains IMR 4350 with a 150. I started at 57.0 grains, then shot 59.0 grains. Both shot very well out to 300 yards though the 57.0 grain load seemed to cluster a bit better. It will take more rounds to determine if what I saw was real, or an artifact of small sample size. I have found, as others have found, that the 4350 powder works exceptionally well in 30-06 bolt guns, if you are looking at maximum velocities. So, I think that is a good place to start.
I want bullets that are jump insensitive. I had too many buds walk away from bullets that shot like a house a fire till the throat moved, and then the combination puked. I don't like seating near the throat. If you ever shot at Camp Perry, there you be, shooting long range and then the range would have to stop, because some fisherman was in the impact area. Everyone would have to unload and wait till the Bay Police chased the boater away. If your bullet was jammed in the throat, when you extracted your round, the bullet stayed in the throat, powder would be every where in the action, and you had to find a cleaning rod to knock out the bullet. Have some experiences like that and you learn to keep the bullets off the lands.
So, I started with a known load, something that ought to shoot well. With a good shooting rifle:
shoots well at 200 yards
Shoots well at 300 yards. And I now have zero's with the new scope on top.
Well how do Federal fusion pulled bullets do at 300 yards:
reasonable with 57.0 grains AA4350
Seems to have promise with 59.0 grs, will need to shoot more to really sort this out.
I have no idea where that eight came from, but this load has promise.
Try the load in a different rifle
known load shoots well at 200 yards
holds the ten ring at 300
has promise
probably a good load.