The Toffees boss described the England international as a "special player" and insisted that he is constantly improving.
"He is a special player and he continues to add something to our team. I see him getting better in lots of ways, his football intelligence and how he can improve his and the teams' performances," Moyes told BBC Sport.
Moyes also said that Everton's victory over West Brom should have been "more straightforward", pointing out that Leon Osman could have put the result beyond doubt late in the second half.
"I thought it should have been more straightforward. We gave away a really shabby goal. We had a great chance to make it three," he said.
Baines scored both of Everton's goals, his second coming from the penalty spot, to consolidate their position in fifth place in the Premier League.