How to Create Abstract Art?

My homework this week for my art class is to create a kind of abstract art. I honestly do not know what to do though! Can anyone give me some ideas? I will use paint, but acrylic or oil paint better to create abstract art? What size brush should I use? Also, what can I do to keep the brush from getting goopy paint brushes? Just plain water is not working so well.

Modern Abstract Art Oil Painting STRETCHED READY TO HANG OPB714 $39.99 Beautiful original modern abstract art handpainted on high quality canva. Each piece is stretched and wrapped on wooden frames. It is ready to hang, no additional frame required. Redefine your living style with this unique and elegant pieces of art created by international artist. Size: L48" x H24" x D1"...

Modern Abstract Art Oil Painting STRETCHED READY TO HANG OPB694 $39.99 Beautiful original modern abstract art handpainted on high quality canva. Each piece is stretched and wrapped on wooden frames. It is ready to hang, no additional frame required. Redefine your living style with this unique and elegant pieces of art created by international artist. Size: L48" x H24" x D1"...

Contemporary metal wall art. Wall Sculptures by Ash Carl $1,895.00 This 7 panel metal wall sculpture by artist Ash Carl will mesmerizeyou and your guests! The handsanded finish on the metal creates a unique 3 dimensional effect. As you pass by, the artwork seemingly moves by reflecting any light in the room. Lighting brings out amazing movement and texture in each panel! The metal and it features an amazing array of detail. These pieces cannot be justified by...

Abstract Bouquet - Greeting Card Share your appreciation in style with this chic thank you card from Pinkerton Design! The card features a charming and artistic floral bouquet set in a unique vase for a lovely way to send your thanks....

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