Q: According to my system preference there is 49 GB to other. How can I delete some of these to give more storage for other projects?

First get an understanding what OTHER really is:

https://support.apple.com/en-us/HT202867

If you want to prune your storage, download from the Internet OmniDiskSweeper and Grand Perspective (both free) and open them.  They will show all of your files and the respective sizes.  Delete or transfer files to an external HDD.  Do not forget to empty trash.

Ciao.

Go step by step and test.

1. Start up in Safe Mode.

    http://support.apple.com/kb/PH11212

2. Backup your computer.

3. Empty Trash.

   http://support.apple.com/kb/PH13806

4. Disk space / Time Machine ?/ Local Snapshots

  Local backups

   http://support.apple.com/kb/ht4878

5. Delete old iOS Devices Backup.

    iTunes > Preferences > Devices

    Highlight the old Backups , press “Delete Backup” and then “OK”.

    http://support.apple.com/kb/HT4946?viewlocale=en_US&locale=en_US

6. Re-index Macintosh HD.

    This will take a while. Wait until it is finished.

    System Preferences > Spotlight > Privacy

    http://support.apple.com/kb/ht2409

7.Try OmniDiskSweeper. This will show the storage size details of the items.

   https://www.omnigroup.com/more

   Select Macintosh HD and click  “Sweep Selected Drive” at the bottom.

   Delete the files you don’t want to keep.

   Be careful. Delete only the files that can be safely  deleted. If you are not sure about any file, don’t touch it.