Naming cities or towns
Naming streets or roads
You must be careful choosing the names you sprinkle through your story. You should also be leery of using the same name from book to book. I mean good-guy Jon in one book might bare no resemblance to bad-guy Jon in another book, but if these two books were released fairly close together, your reader might subconsciously try to find some connection. But that's secondary to what I'm trying to say here.
Within your story, it is important that you be very careful about the names you choose. If you will recall in the Lord of the Rings books, Sarun and Saruman. I always get them confused. Both being bad guys, what's to help keep them separate? How about Eowyn and Eomer? Yeah, I know they are brother and sister, but really, how many instances do you know of where a brother and sister were so closely named? Anybody know a brother and sister named Joan and John for instance?
Those are the instances that always stick with me, but the Silmarilian by the same author abounds with extremely complicated names, names that just might have different pronunciations depending on who is trying to read them. The first time I read the book I made the mistake of passing over the long names thinking I'd recognize them the next time they came up. Some I did, many I didn't, and so the story rapidly became complicated. I have since read the book many times, and still I need to carefully sound out the names and try to file then away with their identity. I love these books, but as you can see, I would have made a few tiny changes.
When I started writing, and even now, thinking up names has always been hard for me. I'm terrible at remembering names anyway. Keeping names different is something I needed to learn to do. Ultimately I decided to lean on the alphabet to a certain degree. As I introduced people to a scene I tried to start each new name with a different letter. Such a tactic served to keep those people who might interact the closest with different sounding names. Of course, I had to make sure the rest of the name was also different.
This works for everything you name, just as the caution must go for everything you name. You might name a town after a hero, but for the most part, it would be difficult to confuse the two. Still, it's not something I would dwell on. It's also common to name a son after a father, but in such instances, it's common for the son to have a nick name, especially when they are together. In my personal life, my husband is named after his father, Donald, called Don. Growing up, my husband was called Donny by his family and friends. When he joined the Army, he shed the nickname. I only knew him as Don. Following what seemed to be a family tradition, I too named my first son Donald after his father and his grandfather, calling him Donnie (and I still do), but I get ahead of myself. My mother-in-law called one day when my son was roughly a year old, and the first thing she said was, "How's Donny?" Of course, the first thing I thought of was my baby, and said he was fine. Following conversation quickly clued me in to the fact that she was asking after her son. I'm thankful my answers applied there as well. Ah but anyway, you get my point.
Try your very hardest NOT to confuse your reader by making your names sound too close to other names. One thing I do is keep a list of names. I like to do that so I remember how I have spelled them, but it is also useful in my keeping them from sounding like others. I keep them in alphabetical order. That also helps me keep from having half a list of characters beginning with the letter A.
What tactics do you use to help you with names?