So I came across smart mirrors about 2 years ago and planned on building my own one day, but only recently decided to make it a reality. My goal was to build a good MM while trying to minimize cost where ever possible.

So I wanted a decent size mirror which I could use in my room and felt 12" x 24" was just big enough, but the good frames for that size were harder to find. I’m sure those with wood work experience and the tools could have made their own custom frame for less, but I got an 18" x 24" frame and then added 4" poplar boards to turn it into a shadow box frame. I filled in the 3" gaps on either side with black poster board cut outs.

For the monitor I used the screen from my 1st laptop (it’s about 10 years old) and got the appropriate LCD control board for it with a 3V power adapter.
But then the next issue I had was that my monitor was really heating up on the bottom third in the back. I mean it was so hot in that region that I could not even touch it there for more than a second at a time. So I ordered a pack of self-adhesive heat sinks and they have worked impeccably. In the future I do plan on getting a PIR sensor if I can program it to only turn off the monitor when I’m not in the room, but keep the RPi running 24/7.

And as you can see from the pictures, I really love duct tape. I even used it to make bands to hold everything in place.
A plus point of keeping the bottom open is that the backlight from the monitor acts as a nightlight which was an unexpected surprise. I was going to add LED strips, but cancelled that plan when I saw this.

Hardware:
Raspberry Pi 3 B+ $38
Raspberry Pi 3 B+ Case with Fan, 3 Pcs Heat Sinks, 5V 3A Power Supply $17
LCD Controller Board $25
12V 3A Power Supply Adapter $10
12" x 24" Acrylic See-Through Mirror, 3mm $37
1.5ft HDMI Cable $5
Easycargo 10pcs 20mm Heatsinks $10
Sandisk 32GB microSD $7
Poster Frame 18’‘x24’’ $12 (had a 60% off regular price coupon from T-mobile Tuesdays)
2 x Black Poster Board 20x30 $6
Two 1/2 in. x 4 in. x 4 ft. S4S Poplar Board $12
Sawtooth Hangers $3

Total: $182

Thanks to @MichMich for developing this awesome software.
Special thanks to @sdetweil who was like Gandalf to me on my MM quest where he helped me when I was stuck at the dreaded Unable to install dependencies while trying to install MM and again guiding me when I was trying to further customize my MMM-Compliments module.
Also special thanks to @Mykle1 who introduced me to his MMM-EasyPix module! I have been loving it.

3rd Party Modules used:
Weekly Schedule
EasyPix
Dark Sky Forecast
Quote of the Day

And here is an amateur edited video of the final outcome.

Decided to change up the decor and added two Star Wars LED lamps that are plugged in to the USB ports on the RPi. I can control them with the remote they came with.

https://smile.amazon.com/gp/product/B07MC7GDJ6/

In case you didn’t find a solution yet, a user by the name sdetweil just helped me with a similar problem with my RPi 3 B+ running the latest Rasbian Stretch.

Here is the link to that discussion for everyone else who is stuck at this step too:
https://forum.magicmirror.builders/topic/9636/stuck-at-unable-to-install-dependencies/8?page=1

In case you didn’t find a solution yet, a user by the name sdetweil just helped me with a similar problem with my RPi 3 B+ running the latest Rasbian Stretch.

Here is the link to that discussion for everyone else who is stuck at this step too:
https://forum.magicmirror.builders/topic/9636/stuck-at-unable-to-install-dependencies/8?page=1

Not every newpaper feed works, so try different ones.

@Mykle1 @sdetweil Thanks, as mentioned, couldn’t have done it without help from both of you!

@bhepler Thanks!
I kept the bottom open thinking it would help with air circulation (and wasn’t worried about light entering from the bottom), but this was a great bonus.
Hehe I actually thought I had gone overboard with that many heat sinks, but I haven’t turned my monitor off even once yet and the back of monitor is still cool as a cucumber!