It is possible to extend the momentum you get from some movement options with Spear by using it right after your movement option, letting you travel more distance than usual.
Bash
If you use Spear right after releasing a Bash, you will go much further than usual.
Jumps
Likewise, if you use Spear right after a jump you will go a little higher than usual. It is also possible to extend your double jump by using your double jump and Spear right after.
When you want to extend a grounded jump then a double jump right after, it's important to keep in mind that you can't throw another Spear right after the first one so you need to wait a bit after the first extended jump before extending your double jump.
When extending a grounded jump, you will also be able to perform a Spear Jump in order to get a little more height. This jump is also very usefull if you want to await the end of the Spear input lock in order to extend a double jump right after.