Note: Many of these articles are very old, and although the technical information is still relevant the equipment mentioned may not be (for example a Stormy cooker was state of that art in 1995, but not in 2021).
Buying boots can be a hugely stressful event, very similar to visiting the dentist for some. Firstly go to a shop that has a good selection, both of models and more importantly sizes! If you have to buy mail order then expect either to pay a lot of money sending boots backwards and forwards, or just except you’re not likely to get a perfect fit. I’d also recommend mail ordering from a shop where you talk directly to a climber/boot fitter, as they can advise you both on what’s likely to fit your foot shape. Firstly don’t make the mistake of going in when your feet aren’t in the mood. If you try and find what fits with feet that are sore after a hard days cragging then everything’s going to feel uncomfortable, leading to you buying a pair of boats. It’s better to come in after a low stress walk, so that your toes are unstressed but with your feet slightly swollen (feet can swell 5%). Trying on later in the day is also a good idea as your feet will have change shape slightly since the morning, with the muscle structure being more relaxed. Make sure you’ve cut your toe nails and try to have cleanish feet! When you’ve got them home wear them for a while to check they actually suit your feet, but don’t expect to break them in without climbing in them, as it’s the high forces you apply through the boot that does most of the stretching.