Forrest Standley Routine pg. 1
The Standley Routine for Horn is an excellent resource for players interested in a thorough routine that includes scale patterns, arpeggios, overtone series slurs, and endurance building exercises in all twelve keys.
The first page of the routine is a wonderful articulation, intonation, dynamic, and tone building exercise. I've made a LoFi accompaniment track for the first page of the exercise that includes drums and a sonically captivating drone to help with timing and intonation.
From the original preface to the Standley Routine:
The purpose of this book is to provide a daily, organized routine that builds endurance and develops flexibility. Most players are familiar with some of these exercises, but a surprising number do not play all scales and arpeggios regularly. Playing these exercises in sequence will develop good control with very little fatigue. After playing for one hour, a short rest is suggested; then complete the book. The reason for writing these exercises in twelve major and minor keys, rather than indicating alternate keys, is that players tend to play what is written and often omit what is not.
A way of starting this method would be to do some of the exercises every day, increasing the range and number gradually. Maximum benefits are achieved by playing the entire routine which takes one hour and forty minutes. Equally good results are gained by diving the time into several fifteen minute sessions in the same day.
This routine is divided into six groups, each containing two scales, two sets of three and four note arpeggios, one exercise for endurance, and one natural harmonica series. By varying the patterns, fatigue is kept to a minimum.
After a vacation of prolonged layoff, a player should be able to regain their previous playing level in three to five days by playing through these exercises, leaving out the extreme high and low notes for one or two days.
As a warm-up for concerts, recitals, and solo performances, I would suggest playing numbers one through five and seven through ten. After playing these exercises, the player will be well warmed up and ready to do their best.