Drawing can be tricky in photoshop. It is generally easiest to draw something out of basic shapes like I'm going to demonstrate here. This flower will be created from simple ovals and circles.
Create a new layer and draw an oval of any color. This will be your petal.
Make many of these and arrange them until it looks like a flower. Then Merge all of the petal layers together so they're now all on one layer.
Double click this layer to get to its layer style. Apply an inner glow. Set the color to #ffffff and the opacity to 70%. Put size to 10.
Next apply Bevel and Emboss. Set depth to 100%, size to 5, and soften to 16.
Set color overlay to what you want your flower to look like. I chose yellow.
Final Result