I recently purchased a Squier Standard. Here are some cheap tweaks that I did to mine.
1. Dress the fret edges. Remove the strings, tape off the neck and with a small file and 600 grit sandpaper, smooth out those sharp edges. While you're at it, go ahead and get some compound and polish the frets. Big improvement.
2. Electronics. Replace the 500k pots with 250k. While you're at it, go ahead and move the middle pickup pot to the bridge pickup (that only involves moving one wire from one tab to another on the 5-way switch). It makes a HUGE difference in sound control. My Squier came with alnico pickups. If yours did, LEAVE THEM ALONE. I learned the hard way by replacing two of them with LACE SENSORS. Big mistake. I reinstalled the originals. There is absolutely nothing wrong with the stock pickups and IMO you'll be disappointed that you spent the money and wasted the time. You will make a better change with replacing the pots and moving the tone control. While you have the pick guard off, go ahead and clean up that mess of wiring and solder all your ground wires to one lug and attach it to one of the switch screws with a nut.
3. Restring (I prefer GHS Gilmours .10 - .4
making sure you knot them at the tuners. Add a third spring to the tremolo and take the time to set it up correctly making sure you end up with the plate absolutely parallel to the guitar body. You will need to tune, adjust the claws, retune, etc., about a half-dozen times to get it set. Verify the neck curvature is set (mine is .010), set your action (I was able to go close to 3/64 at the 17th fret without buzzing), and set your intonation.
My result was a $125 guitar that plays as well or better than some damn expensive ones that I've owned.