Now one of the first things I would suggest doing is setting yourself up a Thrifting Journal.
This can be a notebook, a binder, or just about anything you want to use really. You can even decorate it up if you want to. The essential part of it is that you need to be able to write in it.
One of the main things I would include in this journal which shops you enjoy. Being on the prowl for a deal doesn't mean you should have to frequent establishments that stock a lot of negative items or whose staff is offensive or rude. Make a list of the places that you have visited and what your impression of them is. All hunters have their favorite hunting grounds so why shouldn't you? Also some shops will have discount days that give you 50% off and so on during certain times of day, or days of the week, or on certain types of stock. These are great things to note down so that you can get things even cheaper.
Also I would include a list of which shops carry more of a certain type of merchandise. Who stocks more clothes and what quality are they? Who stocks more furniture? And so on, that way when you are looking for a certain type of item for a project you can start your search with the most likely candidates.
Another essential would be what projects you have completed and are getting ready to start. This helps you to budget not only your funds, but your time and available project space. Getting your own special ritual space, or home decked out in proper witchy style shouldn't be a stressful process. You should be able to take your time and let your creative juices flow allowing you to pour the good feelings and power into your creations. Taking on more than you can comfortably handle is a sure way to end up stressed and not having fun.
Include anything that you'll think is useful to you in your journal. I would highly suggest including drawings or descriptions of project ideas, color schemes, or anything that you feel you'll want to use later. This is your place to keep track of how you're projects are going and what you want your space to look and feel like. Your Thrifting Journal can be your best friend and handiest tool.