Parametric Plotting with Random Coefficients

SF[a_,b_,c_,d_,t_]:={

Sin[t/6]+a*Sin[b*t]Cos[t]+c*Sin[2^d*b *t],

Cos[t/6]+a Sin[b*t]*Sin[t]+c*Cos[16b*t]};
PSF[a_,b_,c_,d_]:=ParametricPlot[

{SF[a,b,c,d,t],SF[a,b,c,d,t]},

{t,0,12Pi},PlotRange->All,

Background->RGBColor["silver"],

PlotPoints->200,Axes->False,

PlotLabel->{"a"->a,"b"->b,"c"->c,"d"->d},

PlotStyle->{{RGBColor["mintcream"],

Thickness[.012]},

{RGBColor[RandomReal[.9,3]],Thickness[.002]}},

ImageSize->600];
PSF[RandomReal[{.5,1.5}]*RandomChoice[{-1,1}],

RandomInteger[{3,12}],

RandomReal[{.01,.1}]*RandomChoice[{-1,1}],

RandomInteger[{3,6}]]