Moving from your walker or Zimmer frame to using crutches is a really significant moment in your recovery. There is just something more "normal" about crutches than a frame and your self image will immediately take a leap in the right direction. But (and yes there's always a but) there are more risk involved in using them.
In particular, take care on floor surfaces you don't know. I've walked into shops and had one crutch disappear right from under me as I discovered that the floor surface had absolutely no grip on it whatsoever. Take it easy, test with extreme caution and proceed with care.
Although some hospitals still supply under arm crutches many are advising against them as they can cause damage to the nerves located in the underarm area. I have a definite preference for elbow crutches (sometimes referred to as forearm crutches) and I suggest you try these out.
As a hip replacement patient it is unlikely you will be using crutches for a long time and so probably won't want to splash out on a pair of designer ones. Yes, believe it or not, you can now get fashionable crutches in all sorts of colours and made from a range of different materials. I particularly like the animal print designs.
Apart from the different styles there is now a growing range of crutch accessories including some very useful bags that attach to the crutch and a choice of different pads and ergonomical grips. Even if you think you'll only be using crutches for a short while these are still a sound investment as they make life so much easier and prevent accidents.
I highly recommend ice tips during the cold weather.
Your crutches should be adjusted for you by your physiotherapist or whoever supplied them. The height of the handle will be at the same level as the creases on your wrist when your arms are relaxed and hanging down by your sides. This should result in your forearms being bent to an angle of about 30 degrees when you grip the handles.
You will start off using two crutches. Lean forward slightly and place your crutches about a foot in front of you. Start to walk forward with your affected leg but move your weight onto the crutches instead. (If you have been told to be non-weight bearing you will need to take all your body weight onto the crutches but in most cases you will be partially weight bearing and can share your weight between your affected leg and the crutches.) As you do this your body will swing forward between the crutches and you can now bring your good leg forward.
When you are more able to weight bear you can walk with one crutch. This is much faster. Place the crutch in the opposite hand to the affected leg. Move the affected leg and the crutch together sharing the weight between your leg and the crutch. Bring your other leg forward.