I've been trying to compose like him for a long time but I've got no idea where to start. What are some of his most used chord progressions? Info like this would help.
First of course you have to master the sonata form, which Liszt used and bent to his purposes. Also learn the cyclical form--the repetition and development of themes-- to unify works.
Liszt was a virtuoso and he played:
- rapid and intricate passages in octaves
- complex and fast arpeggios, scale runs and trills
- with crossed hands
- the sustain and damping pedals to create lush textures.
Liszt would also free improvise, and some of these free improvisations were transcribed and released as compositions.
Use chromatic harmony to create complex chord progressions and dissonant, dramatic effects. Learn how to create tension with augmented, diminished chords and extended chords (9ths, 11ths, 13ths) in all inversions.
Learn harmonic ambiguity, where the tonality or key center of a piece is not clear or is constantly shifting.
Learn modulation (changing from one key to another) and modulate suddenly and unexpectedly.
You could start with this video by Nahre Sol: How To Sound Like Franz Liszt.
Some of her other videos, like the "Happy Birthday in the style of" series, may feature Liszt too.
Liszt also liked to use a rather uncommon (at the time) method of development. He would take a theme and continually modify that theme. Each version of the theme was based on the previous version. There's a Wiki explanation, https://en.wikipedia.org/wiki/Thematic_transformation.
The process used by Lizst (and others) is somewhat (in my opinion) smoother than the processes used in a "theme and variations" composition.