Mrs P - maybe make a list so you can have a plan of attack? I have started an ongoing list of things that need replacing/purchasing as I have really not bothered for way too long. I have found this helps me actually see the stuff I am after when I am in the shop rather than just wandering around knowing I need some clothes but no idea what, ITMS. I had also gotten into some bad habits about dressing down and looking far too slobby so needed to keep myself focussed rather than buying some more comfy leggings, lol!
Similarly perhaps plan colour schemes/colours of interest so you can coordinate the things you do get (a la Rory's suggestion - oh my did I need to see that a couple of months ago).
Most importantly - have fun and make sure you spend it all on YOU!!!! xxxx

ETA My list is - jackets - one denim/one other (canvas?)
long boots flat - brown
Wedges - mushroom
A line skirts - one camel/? dark denim
Tshirts/long sleeved scoop neck - grey/white
Long cardi
shorter more fitted cardi
Some dresses