Rachmaninoff ranked among the finest pianists of his time, along with Leopold Godowsky, Ignaz Friedman, Moriz Rosenthal, Josef Lhevinne, and Josef Hofmann, and he was famed for possessing a clean and virtuosic technique. His playing was marked by precision, rhythmic drive, notable use of staccato and the ability to maintain clarity when playing works with complex textures. Rachmaninoff applied these qualities in music by Chopin, including the B-flat minor Piano Sonata. Rachmaninoff's repertoire, excepting his own works, consisted mainly of standard 19th century virtuoso works plus music by Bach, Beethoven, Borodin, Debussy, Grieg, Liszt, Mendelssohn, Mozart, Schubert, Schumann and Tchaikovsky.  Rachmaninoff possessed extremely large hands, with which he could easily maneuver through the most complex chordal configurations. His left hand technique was unusually powerful. His playing was marked by definition--where other pianists' playing became blurry-sounding from overuse of the pedal or deficiencies in finger technique, Rachmaninoff's textures were always crystal clear. Only Josef Hofmann and Josef Lhevinne shared this kind of clarity with him. All three men had Anton Rubinstein as a model for this kind of playing--Hofmann as a student of Rubinstein's, Rachmaninoff from hearing his famous series of historical recitals in Moscow while studying with Zverev, and Lhevinne from hearing and playing with him.  The two pieces Rachmaninoff singled out for praise from Rubinstein's concerts became cornerstones for his own recital programs. The compositions were Beethoven's Appassionata and Chopin's Funeral March Sonata. He may have based his interpretation of the Chopin sonata on Rubinstein's. Rachmaninoff biographer Barrie Martyn points out similarities between written accounts of Rubinstein's interpretation and Rachmaninoff's audio recording of the work.  As part of his daily warm-up exercises, Rachmaninoff would play the technically difficult Etude in A-flat, Op. 1, No. 2, attributed to Paul de Schlozer.

Answer this question "Did he have any practice or warm up drills or routines he would play in order to become better?" by extracting the answer from the text above.
His playing was marked by precision, rhythmic drive, notable use of staccato and the ability to maintain clarity when playing works with complex textures.