If you are talking like a 5 meter long strip of LED's in 30 cM segments then you cut always at a solder pad.> They pads are marked + and- You must connect + to + and - TO -. The order of the strips does not matter.
Converting Florcesent I cut the 5 Meter strip into the proper length, then peal and stick, then solder jumpers (one each end Plus on one end - on ther other) I cut on ther "Bias" as a dressmaker will call it so that the ENTIRE + pad is on one end and the entire - Pad on the other. Avoids shorts and works great.
The order I tape 'em down in does not matter.
