We've all been there, either forgot to add the ISP header to your board, or simply left it off because its a one time use and gives a large amount of space savings. Or maybe you don't even want to break out programming pins on your board? Adafruit(and others) sell a socket adapter for the Atmega328p (32 tqfp) chip. This is an easy was of adding the bootloader to the MCU before soldering it to the board. The problem with it is that its very annoying to connect to a breadboard. The pins don't match up 1-1 and the experience is one to be desired(when it works!). This small, inexpensive board will not only let you burn the bootloader by providing the correct crystal and voltage, it also lets you connect a FTDI and make sure it will upload sketches.