The Tartan Army missed out on World Cup qualification but raised hopes of being able to reach the European Championships in 2016 with a strong end to their campaign.
Strachan's side have now won four and drawn one of their last five matches, including a surprise 2-0 win over Croatia in October, and Naismith believes that a subtle change of tactics is the reason behind the results.
"The manager has given us the freedom to go and play when we've got the ball rather than worrying about the opponents and what they're going to do," he is quoted as saying by PA.
"We know what we need to do defensively but when we have the ball players are changing positions and making runs more now. That creates opportunities and we're creating more chances."
Scotland will look to extend their unbeaten run to six games when they face Nigeria at Craven Cottage on Wednesday.