Pull unused analog pins to gnd to help minimize noise?

I believe I have done everything I can in software to minimize the temp fluctuations. Does anyone have any ideas obout how to minimize analog noise? I did search Google and multiple people recommended to pull all the unused analog pins to gnd. Also people recommended to use a 0.1 bypass cap. However Im not sure where to place the cap..? Does anyone have recommondations?

Code:

var w = new Waveform(128/* your buffer size */,{doubleBuffer:false, bits:16});
var first = true;
setInterval(function() {
  if (!first) {
    var myarr = w.buffer;
    myarr.sort();
    // cut off first and last 2 elements
    var view = new Uint16Array(myarr.buffer, 2/*sizeof(uint16)*/*2, myarr.length-4);
    var vOut = E.getAnalogVRef() * E.sum(view)/(view.length*65536); // if you attached VOUT to Ao
    var vZero = 0.4;
    var tCoeff = 19.5 / 1000;
    var tempinc = (vOut - vZero) / tCoeff;
    var tempinf = tempinc * (9 / 5) + 32;
    console.log("Temp in C: " + tempinc);
    console.log("Temp in F: " + tempinf);
    //console.log(E.sum(view)/(view.length*6­5536));    
  } else first = false;
  // start it again
  w.startInput(A0,2000 /* Samples per second */);
}, 200);