A truly sleek slicked-back bun is one of the hardest "simple" styles to actually get right — most attempts end up with visible bumps, an off-center part, or flyaways creeping back within the hour.
The difference between a passable slicked-back bun and a genuinely polished one comes down almost entirely to product layering and brush technique, not the bun itself.
Brush section by section rather than the whole head at once — working smaller sections with more passes gets every strand flat before it dries in place, which is much harder to fix once the gel sets.
Save this tutorial for later — pin it to your updos board.
On damp hair, work a generous amount of strong-hold gel through from root to tip using a wide-tooth comb to distribute it evenly.
Using a firm boar-bristle brush, brush the hair straight back from the hairline in one continuous, firm motion, section by section.
Gather all the hair at the crown or nape into a tight ponytail, brushing again as you gather to eliminate any bumps before securing with a hair tie.
Twist the ponytail into a tight coil and wrap it around the base, pinning it securely with several bobby pins in a crisscross pattern.
Use a fine-tooth comb dipped lightly in gel to smooth any remaining baby hairs along the hairline, then finish with a flexible-hold setting spray over the whole style.
Applying gel to already-dry hair, or skipping the firm brush-back step, are the two most common causes — working gel through damp hair and brushing firmly is what actually bonds flyaways down for hours, not touch-ups after the fact.
A firm boar-bristle or mixed-bristle brush distributes product and tension far more evenly than a paddle brush, which tends to just push hair around rather than smoothing it flat.
Edge control has a stiffer, tackier hold made specifically for laying down short baby hairs at the hairline — regular gel works for the main length but isn't formulated to control those short, fine pieces as well.