I'll try to give some of the specifics on how I learned to do it OP. It's always a good idea to form a shield when you project. Any time your body isn't inhabited it becomes a target for all kinds of "things"(that's the kindest way to describe what I encountered).
You always have a tie when you project the silver cord is always on you, it binds the Ka and the Ra together. The only real reasons one might want to cut the cord is to travel to other plains/dimensions and to prevent folks that can see you from twanging it. (where they snap the cord and it pulls you back to your body at rapid speed.) I've met a lot of people that can see projecting persons and have had really nice conversations with them, others not so much.
If you just keep the cord on, your pretty much safe. Your Ka and Ra are connected and nothing can enter your body because you're still completely there kind of anyways. Cutting the cord on the other hand well... not all of your spirit is there and the void becomes a giant calling card to all kinds of entities that there's room for two.
I don't recommend cutting the cord unless you're willing to live with (or rather die with) the consequences. Cutting the cord will not kill you right off, but if you don't make it back in some amount of time (most I've gone is about eight hours or so) or you can't get back to your own dimension, at best you'll stay comatose and at worst you'll stop breathing.
If you still think you want to do it here's how.
The moment you get out you want to grab the silver cord and visualize as ball of light or energy growing from the center of your body on the bed or where ever you happened to project from.
Make it grow until it surrounds you from all sides, it's ok if it projects into the floor or ceiling. Once that's finished inspect the shield by centering it in you field of view between your hands and press in, you should feel resistance from the shield and the light should get stronger. From here you can project and the shield will stay active.
Cutting the cord is a bit more of a chore. You have to give up all of the fear about not making it back and possibly dieing. If you can put all of those worries to rest take the silver cord in your hand and affirm (this is what worked for me you might need to say something just as meaningful)
"I, the master of my body and holder of my own destiny choose to cut this cord. Not as an intent to never return, but as a token of passage. That leaving my physical form will allow me to traverse worlds beyond my own and gain knowledge not within reach of my world."
Twist the cord with your hands like your unscrewing a jar. The cord will snap apart and retract into your body. The portion that's attached to your will fall off and your free.
Hope that helps OP.