Sink low on the bars and own the triceps.
Stay upright to bias the triceps and keep elbows tracking back, not flaring wide.
On parallel bars with an upright torso, the dip becomes a triceps exercise first, every rep drives the elbows from a deep 90 degree bend to full lockout under your entire bodyweight. The chest assists at the bottom of the range, more so if you drift forward, which is exactly why torso angle is the steering wheel of this movement. Few bodyweight pushes load the triceps this heavily, which is why dips have anchored arm training for decades.
Stay as upright as you can and keep your elbows tracking back rather than flaring out. The more you lean forward, the more the chest takes over, so tall torso equals triceps.
To about 90 degrees at the elbow. Going deeper shifts the stress onto the shoulders, and for triceps-focused dips the lockout at the top is the money portion of the rep anyway.
Build up with bench dips, slow negatives from the top position, or band assistance under your knees. Once bodyweight dips get easy for sets of 10 to 12, progress by adding weight with a dip belt.
