I'm currently in the process of getting together a winter walking kit. I've got B2 boots and I'm buying suitable crampons.
Ice Axes though seems more...confusing. What kind of features should I be looking for? I'm not planning on ice climbing, simply winter use on ridges, mountain tops in Scotland/Alpine walking.
For winter walking a traditional straight-shafted mountaineering axe seems most appropriate. This would include products like the very common BD Raven or Raven Pro, and also those with a slight bend such as the Petzl Summit, Grivel Air Tech Evo, and BD Venom.
As there are existing questions regarding length (How do I know what size ice axe I should get?), I'll be brief and only repeat the traditional advice of holding it by the head with your arm hanging down and picking a length where the spike reaches your ankle. (E.g. I'm 185cm tall and use a 70cm axe. I would probably be happy with a 65cm length as well. Others may advise shorter lengths; this becomes more applicable as the slopes become steeper or you don't expect to use the axe for much of the route.)
These days nearly all mountaineering axes have very similar features: a positively-curved steel head and adze, a steel spike, and a straight or slightly curved shaft. A few products deviate from this: Grivel's Futura replaced the adze with a plastic handle and Petzl's Sum'tec has a pick with negative curvature. Ultralight models may use aluminum for the head and eliminate the spike, but these are not suited for sustained use or harder snow and ice.
A negative curvature pick may be useful on technical routes, but is not so good for self-arrest. A straight pick is somewhat old-fashioned and not commonly seen. Note that features on the shaft (finger rests, rubber handles, etc.) may make it more difficult to plunge the shaft. With modern crampons the adze is less used for chopping steps, although it's still quite useful if you need to carve out a platform or snow bollard.
It's not until you get into dedicated ice tools that you run into significant differences: interchangeable picks, being able to select between a hammer, adze, or neither, significantly curved shafts, and very ergonomic handles.
I personally don't use a leash, although some people do. Regardless of your choice, there are two very important rules to keep in mind. The first is Do Not Fall, and the second is Don't Let Go Of The Axe.
Further reading at:
Searching an ice axe for what I would call classical alpine terrain isn't that tough in my opinion. There might be fancy new features and very durable items (T-classification) but those might not be necessary for an ice axe typically used as a walking support.
Most important for me is the correct length of the shaft so that you can actually reach the ground on your not too steep slope. Holding the head in hand, the ice axe should end approx. 5-10 cm over the flat ground. Going uphill you will then reach the ground (typically snow/ice on a glacier). Normal range of the shaft lies between 50 and 70 cm.
The shaft and head both are straight because you simply don't need the curvature. Similar to the stability of the head this curvature will be more important if the slope increases, especially doing ice climbing. A paddle and supporting loop are standard features which are nice to have. You are then able to dig a deadman and you aren't likely to lose the axe. A drift pin at the end of the shaft is also nice to get more grip with the axe while using it as walking support. As for the head you should also care how to carry the axe so that you won't harm your other equipment or people with the sharp edges. Some axes have rubber stopper for this purpose.
The above described ice axe is kind of THE oldschool alpine item per se. I also think it is a must have for lots of mountain tours with moderate difficulty. An important difference compared to the older days is besides the higher resistance of the metal the lower weight.
There are also modern types of ice axes for this scope of application. Some want higher curvature of the shaft or a head with a higher breaking resistance. Just keep in mind where you are planning to use the item.
For myself I decided to get a standard ice axe to be able to do classical alpine tours safely. For ice climbing and higher difficulty terrain, I am planning to get a proper ice tool or an advanced ice axe. There it is also extremely more important that the head won't break because it is an essential item. Material failure could risk your life then. For the standard tours, you still would be able to finish them without major issues because the axe is more of a comfort item if not luxury.
And like for everything: weight matters.
