Group all layers containing parts of flower into one group, and then - i bet you know! - duplicate, move, resize, rotate, repeat!

I also wanted to create special version of wallpaper with berries instead of flowers. Here's how: set foreground color to red, switch to Shape tool, select Ellipse tool, draw circle (hold SHIFT to make it proportional).

Apply the following layer effects:
- gradient: linear, white-to-black, overlay, 10-15%
- outer glow: black, overlay, 30-40%, 4-6px

create new layer, set white color, switch to Brush tool, select small hard brush, put one small dot on top of circle. Then, create new layer, set its blend mode to overlay, select larger softer brush, put another dot on bottom of circle, then hit Ctrl-T and resize it horizontally (so that is it ellipse, not circle).

In another new layer (with blend mode set to overlay and opacity set to 40-60%), use black and white small brushes to give more 3D look.

Group all these layers into one group, and then.... (chorus) - duplicate, move, resize, repeat!