There's a reason that they're called "humBUCKERS"...

1. your Strat with single coils is basically an antenna covered in wood. Short of installing hum-canceling pickups in place of your true singles, you can do a few things to lessen the noise that's inherent to the guitar:
a. shield the pickup cavities with foil tape. I used the copper stuff from Stewart MacDonald that has a conductive adhesive.
b. use a high quality wax potted pickup. Nothing says 'noise maker' like a bunch of exposed wire wrapped around metal poles...
c. be sure that the Strat is properly grounded including a wire to the trem spring claw.
2. If your amp has an effects loop then you should run some of the effects through it but as was previously said, not the gain/overdrive/distortion pedals as they tend to generate more noise than any others and will defeat the purpose of the effects loop. Time-based effects (delay/chorus/reverb/flange) should go through the loop. od/dist pedals can go in the guitar-amp chain.
3. Be sure that the power supply that you're using to power the pedals is regulated at the proper voltage. Some wall-wart type supplies that say they put out 9vdc actually will output 13vdc or higher, way above the 5 to 10% tollerance of the voltage regulator inside the pedal, and will cause excess noise in the circuit.
4. Do NOT use those ground lift plugs. Doing so can cause you serious injury or even death if your circuit fails and your body becomes the path of least resistance to ground.
Seriously, people have died from either using those ground lifts or by pulling off the ground pin on a three prong Edison plug.
5. Once you get your system all connected properly, try turning on each pedal one-by-one and adjusting them to where you'd prefer them to be. Try to recognize which one is generating the bulk of the noise and then try to adjust it out via eq and level adjustment.
Remember to get out in front of your amp a bit to listen to the sound so that you know what others are hearing.