How to burn the bootloader on a standalone atmega328p?

Put the chip into a solderless breadboard.
Get a couple more components:
16 MHz xtal
two 22 pf caps
two 100nF caps
10K resistor.
inexpensive source with low shipping costs: www.dipmicro.com

Wire the chip like a bare minimum Arduino:
xtal across the xtal pins, with 22 pF caps from xtral pins to gnd
10K from reset to +5
Vcc, AVCC to +5
Gnd to Gnd
100nF caps from VCC, AVCC to gnd.

Connect the programmer:
+5 to VCC, AVCC
Gnd to Gnd
MISO to MISO
MOSI to MOSI
Reset to Reset
SCK to SCK

In the IDE:
Select Tools:Board:Uno
Select Tools:Programmer: your programmer

Select Tools: Burn bootloader.

I think that covers it all.