Things to consider before going to the store
Break in Your Feet – Before you try on the hiking boots, make sure to warm the feet up properly. As you walk, your feet tend to swell after about an hour. If you try on the boots with fresh feet, they might not fit right when your feet are swollen. Put on a pair of socks that you will wear when hiking when you try on these boots. Normal socks can distort the fit of the hiking boot. Try on different sizes of the same hiking boot to get a gauge of how each brand of boot will fit your foot. Do not just rely on the sizing on the box or what size shoe you wear with other types of footwear.
Pound for Pound – Hiking-boot weight classifications are a lot like boxers with the heavyweights, middleweights and lightweights. Heavyweight hiking boots usually weigh more than five pounds and are really only for those with extremely powerful legs or a severely rugged hike. Middleweight hiking boots weigh more than two and a half pounds but less than five. These boots are the most common choice among hikers. Then, there is the lightweight group where these boots are really a combination of running shoe and hiking boot. They weigh less than two pounds and, in some cases, less than a pound. Serious hikers will want to stay away from these boots, for the most part. A good thing to remember about hiking-boot weight is that for every pound the boot weighs, that is one extra ton of weight to lift per mile you hike.
(from https://www.livestrong.com/article/223326-the-best-hiking-boots-with-ankle-support/ ? )
When Buying
After Buying
How to break in your hiking boots ?