I take a strip of vector board about 5 holes wide and a few inches long for mounting them. Put them in series, and join the proper end to ground and put the other on the cathodes.Please refer to Damir's drawing, I have to look closely at a built up one before I solder a new string together. It is basically long leg to short, but I can't remember if the long or the short goes to the cathode( and the other to ground ).
regards,
Douglas