Locksmiths are not inexpensive service providers. They do provide prompt service during an
emergency, but the charges can be quite high. In order to avoid having to ever call a locksmith, keep a few factors in mind and take some precautions.
Leave a set of spare keys with someone you trust. This will be a good fallback plan if you ever need one. Also key the phone numbers of your cleaning team or your caretaker into your mobile phone, if they have duplicates of your keys. You should be able to contact them immediately.
Keep your locks in good condition. In winter spray a deicer on them to prevent them from freezing and getting clogged. If the manufacturers recommend any maintenance processes follow them regularly.
Keep the keys of the different entrances separate. Just in case you lose one set, you can still use the other entrance doors.
Keep a list of the master key numbers, in case you have automated locks. Then in case the locks are giving trouble, then once they are opened you will just need to get replacement keys rather than replacing the entire lock.
And above all, do keep the number of a reputed locksmith handy, so that you do not have to waste time searching for one in an emergency.