To write a cursive lowercase f, make a vertical, thin loop up above a baseline. Curve the loop backwards, and bring the pen back to the line. Proceed down past the line and make a thin narrow loop that matches the upper loop but making it curve forward.
Finish the f by making a little line that points upward to the right of the two loops.
To write a cursive uppercase F, start well above the baseline. Draw a line down and backwards to form a shape that looks like a soup ladle. Finish the letter by drawing a hat with a curly flourish on the left.