An action with this trait requires a degree of mental concentration and discipline.
Spellshape
Actions with the spellshape trait tweak the properties of your spells. You must use a spellshape action directly before casting the spell you want to alter. If you use any action (including free actions and reactions) other than casting a spell directly after, you waste the benefits of the spellshape action. Any additional effects added by a spellshape action are part of the spell's effect, not of the spellshape action itself.
Source: Player Core pg. 103
You subtly weave your spellcasting into a performance. If the next action you use is to Cast a Spell, the spell gains the subtle trait, hiding the shining runes, sparks of magic, and other manifestations that would usually give away your spellcasting. The trait hides only the spell’s spellcasting actions and manifestations, not its effects, so an observer might still see a ray streak out from you or see you vanish into thin air.
