There’s only one thing worse than coming up with names for your ocs ,,,,,,,,,,,,,,,,,,,,,,,it’s coming up with their surnames
Some good resources for that include cities, dog breeds, and less common first names. For instance the surname of one of my main characters is Bedlington, from the terriers, and another one is Myles-Morris, which is just the names Myles and Morris stuck together. If you have a baby names book or even a good dictionary, it helps. Also collect interesting surnames from your friends–as long as you ask them if they mind being immortalized in book form that works really well.
Additional ideas: Old timey trades are often surnames (blacksmith, mason, banks, fisher, ect.) Look at street names in your area, types of trees another common one (Maple, birch, cedar), Make anagrams of other words this could even be symbolic (traitor = Mr Attrior) this could recognized though so use carefully. Ask women in your family what their maiden names were or what their mom’s maiden names were. Twist around first names/add a couple syllables (Tanya = Mrs. Tanyani).