Crown-Down Sequence:
SX → S1→ S2 → F1/F2 → F3/F4/F5
Create straight-line access to canal orifice (SX)
Shape the coronal 2/3, confirm working length and smooth the root canal (S1, S2)
Shape the apical 1/3 with finisher (F1, F2). If necessary, proceed to F3, F4, F5