Formal:
* До скорой встречи! (Do skoroy vstrechi!) - This is the most formal way to say "See you soon" and is appropriate for business situations or when addressing someone you don't know well.
* До свидания! (Do svidaniya!) - This is a more general goodbye phrase that can also be used to mean "See you soon".
Informal:
* Скоро увидимся! (Skoro uvidimsya!) - This is a more casual way to say "See you soon" and is appropriate for friends and family.
* Увидимся! (Uvidimsya!) - This is the shortest and most informal way to say "See you soon".
* До встречи! (Do vstrechi!) - This is another casual way to say "See you soon" and is often used by people of all ages.
Adding "very soon":
You can add "very soon" to any of these phrases by adding "очень скоро" (ochen' skoro) before the greeting. For example:
* Очень скоро увидимся! (Ochen' skoro uvidimsya!) - This literally means "See you very soon!"
The best way to choose the right phrase depends on the situation and your relationship with the person you're talking to.