The lovely @blueangel06661 suggested it would be a good idea to have a thread about cosplay tips and resources and such so here goes! Please feel free to add your own or ask questions. I'm certainly not an expert on cosplay, but after a few years, here's some things I've learnt.

Let's start with the costume. It doesn't matter if you buy it or make it. Seriously. If you can sew, and decide to make it, I suggest using a pattern that is similar to what you want, and just alter it as needed. Mock-ups out of spare fabric are a great idea. And don't be afraid to ask for help. All of my hand-made cosplays had a lot of help from my Mum. She's much more experienced with sewing than me. And be prepared for it to take time and patience. If it gets too frustrating, just walk away. Come back to it when you're ready.
If you buy your cosplay, it will likely be from somewhere in Asia. As their sizes run small, I recommend figuring out which size you need and then buying the size UP from that. If it's too big, it's very easy to make it smaller. But if it's too small that's much more difficult.

Once you've got your costume, CHOOSE A WIG. If you've chosen a character with similar hair to your own, still wear a wig. Trust me I've tried with my own hair (and I have LOTS of hair) but it's just not the same. Anime hair is big and bright and only a wig can really give you that look. Also, it will make your face look smaller :-) I get most of my wigs from eBay. I steer clear of the really cheap ones, but there's certainly no need to spend $100 or so. I usually spend $30-$40 AUD and get something decent.

Finally I want to talk about make-up. I'm not great with make-up as I only wear it when I cosplay. I usually YouTube a couple of tutorials for the look I want, and I always do a practice run or 2. If your character is female - false eye-lashes are a must. I could go into this a lot more, but I don't wanna bore you. If you need help with falsies, hit me up. Many cosplayers wear contacts, and they look amazing. I choose not to because the costume ones, even if of a high quality, can cause damage to your eye. If you feel comfortable wearing them, feel free. But I have seen other cosplayers with eye injuries from contacts, and I've found them rather painful and uncomfortable myself, so please be careful.

Whatever project your doing, you can almost guarantee someone else has done it before. And they've probably made a video or blog about. So google it, watch and learn from what others have done, and most importantly: HAVE FUN!