OP, the best way to get a nice triple pleat heading is to use buckram for the heading and to work out the measurements. It's probably not the easiest type of heading to begin with, but can be done with patience. You need a large work surface, and to be able to double check all your measurements etc. The site I mentioned before has loads of videos about curtain making that you might find helpful.
If you are a novice, then perhaps it would be easier to stick with a pencil pleat type heading, or you can you a 'flop over' which looks nice for bedrooms etc. Until you have made curtains, you don't really appreciate how hard it is to be working with large pieces of fabric.
You mentioned that you had a whole house to do. Why not source cheaper fabrics, ebay and factory shops, and do simpler curtains for some windows, then pay to have your triple pleats done (although IMO double pleats look nicer, and more contemporary!). A good curtain maker is worth their weight in gold, and will be able to deal with different fabrics and patterns - what looks good on the roll might look terrible made up if they don't distribute patterns properly for example.
I've attached a pic of one I have made, I am definitely an amateur but was quite pleased with it. If you have the time and patience, then you can do it, but it is not the easiest thing to start with. Good luck