The Spaniard has seen his side lose only once in their opening 17 league games as Everton sit fourth in the table, two points behind leaders and city rivals Liverpool.
A 2-1 victory at Swansea City on Sunday ensured Everton kept pace with the top three, but Martinez believes his team are yet to peak heading into a busy fixture schedule.
The 40-year-old has refused to talk about his side being title contenders and will only set targets in April.
"We're in December and it would never be foolish to speak about our league aims," said Martinez, who has confirmed that defender Leighton Baines is likely to return from a fractured toe against Sunderland on Thursday.
"We are trying to be very, very consistent. One defeat in 17 is a real consistent way of performing and the next step is to carry on developing and performing.
"I don't think we have reached our full potent yet and that excites me.
"We want to get to April with biggest amount of points we can, then we can set targets.
"One defeat in the league shows it has been a promising start. We have been getting the squad looking to do things in a more open-minded way, trying things, being brave.
"All it is a good platform for a strong second half, we don't assess it halfway through."
Everton face Sunderland and Southampton at home in their final two matches of 2013 before travelling to Stoke City on New Year's Day.
