Hiking boots
You need to look at how the upper is attached to the last. They are usually stitched together. These are called seams and the more seam the better. Keep in mind though, the more seam the better the fit and usually the more the hiking boot will cost. Single stitched hiking boots are usually less expensive, this does not necessarily mean the are bad. If the fit well you might want to buy them, just remember they probably will not last as long.
The leather is something else to consider when pick out a pair of hiking boots. Some have the smooth side of the leather turned out. These will show scuff marks very easily and look banged up. Choosing the rough side out on the leather will stay looking nicer longer. After all, they are all ready roughed up.
You need to look at the sole and decide which is best for you. Hard sole work better on grassy areas or dirt. Softer soles do good on rocky areas. Depending on where you go fishing the most will be the determining factor on which sole you use.
Other things to think about when you are purchasing a pair of hiking boots are the tongue, is it one piece or two. You want one piece. Also look at the type of lacing the boot has. Eyelet is the strongest but not the fastest when putting on your boots. Speed hooks are good but don't provide the best in secure lacing. The manufactures have come out now with d-rings. These are a great choice giving you the best of both worlds. Most manufactures will do eyelets on the foot part of the hiking boot and then d-rings on the ankle part.
So many things to think about. You may end up with more then one pair of boot, if you can afford them. Have fun finding a pair that is right for you and most of all have fun fishing.