[Hardware Hacking General] XXCoder:
This was for my Touchpad cover review and how-to, but this may be useful for cleanly placing screen protector on your device too. If you're trying to place screen on phone and not large tablet, just use 2 tapes for hinge not 4, and make it shorter strips of tape. This is with screen protector type that is sheet with cover on each side to protect it till it's ready to be used.

Here is what I did to place it on very cleanly.

Prep before steps 1-4: Get one screen protector, lint-free pad, paper card from package, and clear tape roll and brown tape. Also grab scissor. I used electric tape in place of brown paper and it worked too. If you have to use restroom as dust-free area by showering, also grab plastic bag to protect your tablet from steam.

(This steps is before you bathe if you decide to do it this way)

1) Pick a nearly dust-free area.

2) Remove case if any, then clean tablet screen - at this stage it do not have to be perfect but there should be zero oily sheen but little dust is fine. Leave case out till completed all steps.

3) Grab screen protector and align it on tablet, but DO NOT REMOVE any covers on it. Tape it on one long side with in least 4 brown tapes so it will be able to act as "door". It should be able to flip up and down without getting misaligned. Yes, it means you will have tape on touchpad itself. Be generous and use 3 inches each point on one side. Two inches on screen and in least one inch overshoot and tape on touchpad. So it will not loosen and cause misalignment. You can clean tablet after you're finished anyway.

4) Put 2 "handles" on other side corners by partially folded over tapes. It should not stick to tablet at all. This is so you can easily lift it again without actually touching cover at all.

(If you went for steaming room to get rid of dust, first put tablet in plastic bag, seal it so steam cannot get in, then bathe. Have fun bathing. Do not open restroom door and turn on vent till completed.)

Prep before next steps: Make 3 or 4 segments of clear tape for use as dust remover. Tape it to something so most is hanging off edge.

(if bath method, take tablet out of plastic bag)

5) Now this is when you want perfection. Lift screen like door upwards, use close light and lint-free cloth to really clean the screen on touchpad itself. Wipe the bottom sheet of screen protector, wait while tiny amount from that settles on touchpad, then wipe touchpad again, seeking perfection.

6) Now, with very clean touchpad, hold on one of handles as you peel off the bottom sheet off the screen protector.

Never, at any point, touch the screen protector bottom or edges! This is likely cause your screen protector to get dust/oil from fingers!

7) Carefully lower cover on touchpad, use both handles. You should try to avoid creating any bubbles. There is 2 kinds, ones caused by uneven landing and other by dust. Dust ones is usually smaller. You can lift it up again using tape handles and use one of clear tapes to pick up dust off screen or cover sheet. Clear tape is much stronger stick so it will grab dust even off cover sticky side.

You should have cover on completely, and it should be mostly air-free. Don't remove top cover yet, you will need it to protect cover from paper card and your fingers as you rub near center air bubbles out. Rub cover under tapes that's acting as hinges outward so there is less air bubbles hiding under it.

9) Carefully peel the "hinges" tapes from tablet but not the cover side, leave tapes there.

10) Finally remove the front protective sheet from cover, taking tapes off with it.

(if you are in restroom after bathing, you can now leave, taking stuff with you to more comfortable area)

11) Carefully push any remaining air bubbles out to edge using fingers (not nails) only. If it is dust type it is basically too late since you have no safe dust/dirt free way to lift screen again. But luckily you can get rid of nearly all air out of it by rubbing air bubbles to edge from few different directions, leaving pretty much nothing but dust speck there. My tablet had 2 of those and it is pretty much invisible.

12) Finally clean the touchpad tape dirt off it, then when touchpad is clean again, place it back in case again, if any.

Enjoy the nearly perfectly placed screen protector on touchpad!