Many people have a short list of folders that they usually save to. Office lets you choose your default folder, and pin other folders to the list for faster access.
With an unsaved file open click the Save icon on the Quick Access Toolbar or press CTRL+S to open the Save dialog.
From here you can select a folder and click Default to make it the default folder for future saves.
To pin other folders to the list for quick access hover over the folder name and towards the right side of the dialog select the pin for that folder. You can pin multiple folders to the list.
The next time you see the Save dialog box your default folder should be selected and your pinned folders should be quickly available.