Why use Google Maps?
Plotting out the destinations you want to go to ahead of time helps you orient yourself ahead of your time and plan more efficiently based on how close things are to each other. I'm going to use my most recent Mexico City trip as an example for how to go about this process.
Step 1: Research
Research where you want to go in the city you're visiting. Visit blogs and TripAdvisor to gather information of the best things to do, see, eat, and drink during your stay.
Tip: Read reviews for restaurants
Step 2: Create a Google Map
1. Open Google Maps.
2. Hit the menu in the top right (3 stacked lines)
3. Choose "Your Places" from the side menu
4. Hit the maps tabs
5. Click on "Create Map"
6. Name your map
Step 3: Plot all the places you want to go
Start adding pins to your map so you can see where things are in relation to one another. You can add multiples layer, colors, and even icons. Another wonderful thing about this is that while you're plotting your adventure you'll start to understand the geography of the city.
Step 4: Set up a tentative Itinerary
Now that you have some things plotted for the things you want to do, you can set up your itinerary based on what's clustered together. For example, if you're going to a museum in one part of town, you can have lunch in that same part of town. You can plan your days on proximity to maximize your time.
Tip: Check the times and dates that museum's and churches are open to avoid disappointment. For example, a lot of museum's are closed on Mondays.
Hope this helps you plan your trip!