Normally when I make my own plot functions, I make a construct :
op <- par(\"mypar\"=myvalue)
on.exit(par(op))
which is the standard way
dev.off() is the best function, but it clears also all plots. If you want to keep plots in your window, at the beginning save default par settings:
def.par = par()
Then when you use your par functions you still have a backup of default par settings. Later on, after generating plots, finish with:
par(def.par) #go back to default par settings
With this, you keep generated plots and reset par settings.