If you can take the photo yourself, you can upload it to
http://www.idphoto4you.com/ and their website (free and nothing to download) lets you crop it and adjust it to UK passport photo size... or US or Australia or Afghanistan if you need it!
You just choose what size you'll print a photo (4x6 is standard), take it to any place that prints good quality photos (I took them to Costco in the US and Boots - I would not recommend Boots for this- and Jessop in the UK- infinitely better than Boots).
It puts 4-8 passport photos (depending on which country) on the 4x6 photo (or whatever size photo you say you'll print them as) and you just have to cut at home them yourself.
I've done it this way in the US for my Fiance Visa and FLR(M) pictures and in the UK for DH's passport photo for my FLR(M) application. I had no problems either time.
Just follow the instructions on their website and make sure the photo you take of yourself is good quality and high resolution.
My photo looks beautiful!
Much better than if someone else were taking it- they'd care about adhering to the photo requirements but not so much how you actually LOOK.
