Sensor reading inside loop -best way

yeh..
Use timebase to do procedures at different intervals
e.g.

long timenow; nexta;nextb;
.....
void loop()
{
  timenow=millis();
  if (timenow>nexta) proca();
  if (timenow>nextb) procb();
}
void proca()
{
  nexta = timenow + interval;
  do stuff....
} 
void procb()
{
  nextb = timenow + interval2;
  do stuff....
}