Be sure to use a heavy saucepan.   You'll need a 2 quart size.  Butter the sides.  Add both sugars, half and half and salt.

Cook over low heat until the sugars dissolve.   Stir constantly.   I was a one-man show today so the pictures of each cooking step are scarce.  I discovered right away that I'm not coordinated enough to stir with one hand and take photos with the other.  I kept moving my camera around in circles.

After the sugars dissolve, turn up your burner to medium and keep stirring until the mixture boils.  Turn down the heat a tad, keep stirring until the mixture reaches the soft ball stage or 234 degrees.  I highly recommend using a food thermometer.

As soon as you reach 234 degrees, hopefully before your arm falls off, remove from heat.  Add vanilla and butter. DO NOT STIR!  In fact, take the next 5 minutes off and let the syrup and your arm cool for a bit.  Ice down your stirring arm.

After 5 minutes, add pecans and beat with a heavy wooden spoon until the mixture has  thickened and lost its glossiness.  This is the hardest part to judge.  You want the candy to set up as soon as you pour it out, but you don't want it to get so hard that is sticks to the spoon and doesn't pour.    I make little test runs.  Drop tiny bits onto your prepared pan which has been covered with waxed paper or a Silpat mat.    This will help you decide if the pralines are ready.  Drops from spoon easily.  Check.  Sets up on the pan.  Check.  You're ready to rock and roll.   The praline mixture will stay creamy and not get hard like peanut brittle.   Now before you start spooning out the pralines, you'll need to clear your pan of all your little test runs (read: eat them).   Drop the mixture from a spoon.  I used a tablespoon and wound up with about 36 glorious pieces of Southern Pecan Pralines.

Let them sit on the pan until they are completely cooled.   Serve them in pretty dish.