Firstly if there is a procedure in the Flight Manual/Pilots Operating Handbook then use it since this is specific to type.
Retracting flap invariably results in a certain amount of "sink" - how mujch depends on a/c type, amount of flap retracted etc.
However the essential ingredients of a "Go Around" are:-
1. Select FULL Power (Rudder to keep straight).
2. Adopt the correct attitude to climb away at best ANGLE (not the same as best rate) - see appropriate speed in POH etc.
3. Immediately get rid of the "drag" flap - the bit between full flap and flap setting for short field take off (typically).
4. When at a safe height retract the rest of the flap. What constitues a safe height depends on type etc. Older types of a/c with inferior climb performance might mean waiting till 200/300 ft agl. Other types 100 ft agl might be quite acceptable.
5. Usual stuff about turning towards dead side to see departing/rolling traffic etc. - this bit is called "Airmanship"!