Homemade Caramels

I've always wanted to make homemade caramels, but I've always been too intimidated to try.  Then I got my latest issue of Martha Stewart magazine and there was a recipe for homemade caramels, I took it as a sign to finally give it a try.  I won't blame Martha for the way they turned out as it was probably a combination of things.  They are actually still quite tasty they just didn't get quite as hard as I would have liked.  I think I was a little paranoid about taking them off right when they reached the correct temperature and didn't leave them on the heat quite long enough.  My husband still gave them a thumbs up.  They were really easy to make and I'll definitely be giving it another try.  I've heard Ina Garten's are pretty tasty too, might give those a try on the next go round.   

Here's the recipe from Martha Stewart

Ingredients

• Vegetable oil, for baking sheet
• 2 cups heavy cream
• 2 1/4 cups sugar
• 6 tablespoons unsalted butter, cut into pieces
• 1 1/4 cups light corn syrup
• 1/2 teaspoon coarse salt
• 1/2 teaspoon pure vanilla extract

Directions

1. Lightly brush bottom and sides of a 9-by-13-inch rimmed baking sheet with oil. Line with parchment, leaving a 2-inch overhang on long sides; lightly brush parchment with oil.
2. Bring cream, sugar, butter, and corn syrup to a boil in a large saucepan over high heat, stirring until sugar dissolves. Reduce heat to medium-high; cook, stirring occasionally, until caramel reaches 248 degrees on a candy thermometer, about 15 minutes.
3. Immediately remove caramel from heat, and stir in salt and vanilla. Pour caramel onto baking sheet, and let stand, uncovered, at room temperature at least 8 hours and up to 1 day.
4. Lifting by parchment overhang, transfer caramel to a large cutting board. Cut into 3/4-by-1 1/4-inch pieces; wrap each piece in waxed paper or cellophane.
   
   
   Have you made homemade caramels?  How did they turn out?  Any tips?