At the moment my focus is on completing my daily target of steps, currently set at 8,000, and on completing a period of exercise lasting at least 30 minutes on at least 6 days each week. So far, except on days I've had a migraine, I've met my target. I've deliberately set my targets low so that I can achieve them as, if I fail to meet them too often I know I'll give up. Most of my interests are sedentary so completing at least 8,000 steps each day is an achievement and now I've become more used to moving regularly, I'm easily taking over 10,000 steps each day. I have no plans to change my target on the fitbit in the near future but in my mind I am going for the 10,000 - I know I'm kidding myself, but it's working!
The target of a 30 minutes exercise period on at least 6 days a week is the one which requires the most effort and I usually do this by walking around the house and/or garden before I have my breakfast. This means that I have done about a third of my daily step target before my day has really started. My day off from this is the Saturday as band practice starts early so I don't always have time, and know that I won't want to do it when I get home. Ideally, I'd go out for a walk every day but I still have a lot of days when I can't face going out of the house (unless I'm teaching or meeting someone), so exercising around the home is a good compromise. If I feel able, then I'll do another walk around the village or along the canal later in the day.
My favourite feature on the fitbit is the reminder to move at least once an hour. I've set my day as 9 am to 6 pm so, if I haven't taken at least 250 steps during each hour, the fitbit vibrates 10 minutes before the hour is up as a reminder to move. According to the blurb in the help documents, moving for short periods at least once an hour can reduce the negative effects on a person's health of sitting for long periods of time. Movement, as in walking and climbing stairs, is definitely easier even after only one month of exercise, and that's something which will continue to to improve.
You can also use the fitbit to monitor your weight. I'm not using this feature yet, but will get round to it eventually. I still need to lose weight but am waiting until the depression is less of an issue - there are much bigger problems to focus on first. I'm aware of slight changes to my body shape already, just from the regular exercise, with clothes feeling looser than before.
If anyone is thinking of getting a fitbit, I'd wholeheartedly recommend it. I'm kicking myself for dithering so long about buying one as I can honestly say that it has been a life changer for me.