A concrete practice-tool routine for Rakan, built around its real cooldowns and ability costs.
Rakan periodically gains a shield.
Do nothing else for five minutes. The passive is the piece nobody isolates, and it is the only part of the kit that is always available.

Rakan periodically gains a shield.
Flings a magical feather that deals magic damage. Striking a champion or epic monster enables Rakan to heal his allies.
Dashes to a location, knocking up nearby enemies on arrival.
Flies to an allied champion granting them a shield. Can be re-cast for free for a short duration.
Gains Move Speed, charming and dealing magic damage to enemies touched.
Practice tool lets you reset cooldowns, which is useful for learning a combo and useless for learning a champion. Turn the reset off and cast on the real timings — knowing what an ability's downtime feels like is most of what separates a comfortable champion from a new one.
Rakan is mana-gated, which is the real limit on how often you can contest a wave early.
Unglamorous, and the highest-value five minutes of the routine. Ranged champions have completely different tower-farming patterns, and this is where you find out which one you are actually playing.
These are the designers' words, not ours — the tips shipped in the client for Rakan.