It can be so hard planning a festival outfit, take it from me, a person that has had several meltdowns weeks before Parklife when trying to find an outfit.
I think the hardest thing for me, personally, is trying to find an outfit that you know is not only going to be comfortable, but looks good too. I ordered about four different outfits in the lead up to Parklife, but ended up being disappointed in all of them when trying them on.
Let's be honest, there's nothing worse than having an outfit planned out in your head, trying it on, and it looking totally different to what you thought. That's what I found with all my festival outfits, before visiting H&M at my local retail park.