If I am going to eat the whipped cream the same day, I sweeten with powdered sugar, the corn starch in the powdered sugar stabilizes the cream quite well.
If I need it to last a day or more, I stabilize with gelatin, gelatin changes the texture a bit, makes it more spongy, but it holds up really well even when it needs to stay out of refrigeration for a while. This is the method that I use.
I whip the cream just until I can tip the bowl and it doesn't slide, nice and stiff, but be careful, you don't want to whip it too much.
Wilton Stabilized Whipped Cream Recipe - Food.com - 79506
I use the microwave. I put the gelatin and water in a small glass pinch bowl and let soften for a minute or two and pop it in the microwave until melted, about 10-15 seconds (you'll know when it is ready when it is clear).