Via personal experience, experience working with 100's of clients, reading what others have talked about, and by reading and critiquing of primary scientific research, i suggest each muscle should be trained at least once every 5 days.
There are several ways to do this, but I think the easiest is through an upper/lower split, emphasizing one movement plane on one day and another on the other day.
For example:
Lower 1: Squat emphasis (5x5), squat ancillary 1 (pitcher squat or split squat) 3x8, squat ancillary 2 (single leg rumanian deadlift, lying leg curl alternating legs) 3x10, core and stabilizer work
Upper 1: Vertical Emphasis: Over head press and pull ups (5x5 ish), shrugs (3x5ish), horizontal ancillary work (resisted push ups and supine rows), shoulder ancillary work (rotator cuff, lateral rasies,scapula depressions)
Lower 2: Deadlift emphasis (5x5), deadlift ancillary 1 (lunges, either traveling or stationary) 3x8-10, deadlift ancillary 2 (glute ham raise, glute hip barbell bridge, hip pull through) 3x10, core and stabilizer work
Upper 2: Horizontal emphasis: chest press and bent over barbell/t-bar rows (over hand grip) 5x5, vertical ancillary work (pull downs, single arm Over head presses) 3x8, shoulder ancillary work (scaptions, external rotations, face pulls, etc.) 3 x12
Br