After my hardwood was installed my 3 interior bedroom doors are now about an inch from the floor. What can I put on the bottom of the doors to get them closer to the floor. I really don't want to order custom doors.

Unfortunately this happens all the time. Carpet & pad is about 1 1/2 " plus builders will allow too much clearance on top of that.
What do your doors look like? Do you think some sort of trim can be incorporated with the door , at the bottom ? Without looking like an eye sore?

If you have central air and central heat, your suppose to have at least an inch gap under the bottom of the door, or a vent into the room for return air flow, or your HVAC system will not run efficiently.

The doors are standard builder issue white doors.
I would think some type of trim on the bottom would work.
Any trim recommendation would be appreciated.
Maybe something that can be cut and glued onto the bottom.

I dont know how great that's going to look .
But if you like ,I would look at a moulding supply house, and see if something strikes you. Places that specialize in mouldings have a far greater selection than big box stores. It's just a matter of taste.

Yeah, that looks funky being that high up from the floor. Save yourself some frustration and buy new doors.

I have successfully added a strip to the bottom of doors and using multiple layers of automotive Bondo, concealed the joint enough that the new paint made the door look contiguous. Was the effort worth it? No. It cost my client more than replacing the doors would have. If doing the work yourself, you might consider that route but assume a collective period of about 4 hours for each door, plus repainting.

Geez, What we do for customers

Like a 1x2?

We talking hollow core doors? If so just cut to hollow area, stick new board in there extending to the length you want it, float it even with existing veener using bondo and other wood filler, and then reface with new veneer. Does that sound easy?? lol

Let's compare how much all this works out to per hour , about 8 bucks . As compared to picking up a basic bedroom door and it's done, and no jimmy rigging. Am I missing something. Or are we just having fun know?

Well, the doors I patched up for my client were a little odd, so matching them would have been difficult. So in my case, it WAS worth it to the client.