Initially she only worked in watercolor but Heleen decided the paper was getting too small. This made her switch to oil, after studying this medium in Amsterdam with well-known artist Rik Lina. Later on, she discovered the advantages of watercolor canvas and renovated her style. It became less realistic and more colorful because she used the unpredictable creativity of this medium.
Heleen can often be found at the top of Mount Scenery were she makes dramatic drawings of the rainforest. She has once set camp on the mountain for more than four weeks. These drawings have resulted in large paintings of oil and watercolor on canvas. Heleen also did a mural in the Sacred Heart Church, a Roman Catholic Church in the Bottom on Saba. Here she combines rainforest scenes with religious symbols.
Another source of inspiration for Heleen is the underwater world of Saba. She made drawings while diving together with her husband in the pristine crystal clear Caribbean Sea. This resulted in the series of paintings of dolphins and other underwater creatures.