As someone who has had more EGDs than I can even count, how about if I give you a patient's perspective? I've been getting EGDs regularly since the mid 90s, and I've also had an unmedicated colonoscopy within the last couple years.
In the pre-procedural area, your typical patient is going to be scared and uncomfortable, particularly if they've never had a 'scope before. If they're having a colonoscopy, they're likely going to be fatigued from having been up all night pooping their brains out. If they didn't get the advance warning to purchase wet-wipes during their cleanse, they also have a ring of fire where their anal sphincter used to be. If they haven't been actively rehydrating, they may be a difficult stick for the IV start. If they're having an EGD, they're probably going to be starving and thirsty and dehydrated. Regardless of which procedure, they're probably at least a little scared about what is going to happen, unless they've been through it before.
If you haven't observed each type of procedure, I highly recommend it. That way you can explain the nitty-gritty details to the patient (yes, the MD is supposed to do the actual informed consent, but as the nurse, you are going to be the one spending face-time with the patient before the procedure). You can explain to the patient that you'll have them change into a gown, get vital signs, start an IV, take a short EKG strip on them, have them sign papers, etc., then they'll be wheeled to the procedure room where the lights will be dimmed, they will be placed on their left side, and if having an EGD they will be given an anti-bubbles liquid to swallow, they will be strapped down so they won't move during the scope, a hard plastic thing will be placed in their mouth so they don't bite the tube, and medicine will be inserted into their IV for the procedure itself. Then after the procedure, they'll wake up in the recovery area and be there until the sedation wears off enough for them to go home. Also, tell them now, when fully aware, that it's normal for them to forget things that happen later in the day.
A few things for post-procedure -- don't tell your colonoscopy patient that it's okay to pass gas freely because it's just the air that was pumped into them. Unless you know for a fact that they had a completely clean bowel, you could end up having to wipe up some residue if you have them fart at will. (Fortunately I was unmedicated for my own colonoscopy because I wanted to watch it myself, and I had seen the little bits and pieces that were still inside me. Had I not been fully conscious, I would have followed the nurse's advice and left skid-marks all over the bed!) Don't panic if the O2 sats are low for a sedated patient -- just remind them to breathe (some of us kind of forget that until the sedation wears off). Make sure that the responsible adult escorting your patient home knows that it's normal for the patient to forget stuff for several hours.
I hope that helps with the patient's perspective a little bit.