On web https://www.blocklayer.com/spiral-templates create a spiral with widther gap. Click on SVG button and right click on generated spiral Save As → To computer

Import generated spiral image to XCS. Select on spiral a UNGROUP. Right click on top of spiral description and DELETE. Double click (Node editor) on spiral and move last spiral node down to close spiral. NOTE: You can overlap the line. Select spiral a change size of spiral. HINT: Different sizes makes final assembly more easier.

The number of spirals depends on the size of the heart.

Insert two Heart shapes. One heart shape will be bottom part for roses and another heart shape will be outline. HINT: You can do another version with two pieces of plywood glued together but instead of middle engraving you will use cutting.  

If you want final decoration to hang it you must do a two circles for a rope.

For roses I used 270gsm cardboard. After you cut spiral shape you must rotate end of spiral and go to inside. HINT: Prepare your heart shape before you will glue it! 

For gluing I used Pattex glue for wood.