The size and placement of batteries for ANR headsets is an important consideration. The type and amount of padding in a headset also can make a difference. Padding under the headband and around the ears is most important, but some headsets can be comfortable for long periods with minimal padding. Again, this is something you'll have to test for yourself. If you are tall, keep in mind how headset padding can affect the amount of clearance between your head and the top of the cabin.
All headsets adjust to some degree.
Most have adjustable headbands to help you position the ear seals comfortably. But most headsets were originally designed and sized with men in mind. Petite women will want to be sure to choose a headset with a band that adjusts small enough to give them a proper fit. The microphone boom on most headsets also is adjustable. Some pilots prefer a fully adjustable boom so that they can position the microphone with great precision.