Varies by practitioner- there’s a lot of methods for both, most based around visualization until you develop enough skill to feel energy and feel it being done, but I can’t make images with my mind due to anphantasia.
Warding isn’t permanent, it degrades over time unless you have an energy source for to replenish itself on, so even if your friend did ward your space, unless he maintains it, it doesn’t last forever and it’s not perfect- real smart spirits, particularly shadow creatures/people can look for holes in it, learn to move around it’s vibrations by adjusting their own etc.
I personally use a banishing ritual that calls upon angelic forces in eight directions- one for each wall of the home and one for each corner of the home, to banish and protect- it’s real short and easy and I found it in a book called Angelic protection magic by Ben Woodcroft. Most on the forum recommend the LBRP for banishing, but to me it has way too many steps, it’s hard to remember etc, and there are quite a few versions to choose from now that it’s been adapted to so many different outlooks in life.
I also use my own energy, by pushing it out from myself until it flows over every surface of my home and sorta encases me in a giant bubble- which is basically what warding is, but it also pushes out anything unwanted.
You can google or search the forum for banishing shielding and warding techniques. I also created a servitor that can do it for you if you summon her until you gain the skills yourself, but I still recommend developing the skills, so that you don’t need to rely on something else.
As far as lhp goes, Eh. I don’t subscribe to the way people view rhp or lhp and make each decision based on my internal compass and not the worlds.
I’ve known angels that could kill and torture someone, and demons that heal so. I’d take all that shit with a grain of salt.