Bear in mind this is just how I make heart shapes with rhinestones. I am sure there are other ways - feel free to play with your rhinestones to find what works for you and gives you the final look you are after.
When adding rhinestones to your manicure, you want to apply them when your polish is still wet. If your manicure is already dry and you decide you want to add rhinestones, apply a coat of clear polish. Make sure it is not a quick-dry polish - you need to give yourself time to apply the rhinestones while the polish is wet so that they will stick. Remember to seal your rhinestones on with a coat or two of top coat to help them stay on longer.
Start by placing one rhinestone where you want the bottom point of the heart to be.
Next, make a line of three rhinestones above the first one. It can be a little easier to line them up if you start with one directly above the first rhinestone, then add one to either side.
Now add a line of five rhinestones.
On the next line you will use four rhinestones - two on each side. Leave the middle open.
Finish off the heart with two more rhinestones: one in-between the last two on each side.