GTS.
I had the same dilemma the day I went to put on my stripes. We had a look at the HQ HJ promo brochures and even the Trax model sandman version but still wernt sure what looked best. In the end I think we went with the longer tapered end to the front and the stumpier end to the rear. This put the thickest part of the stripe over the wheel arch. No-one has ever told us we have them on backward (at least they are not upside-down)
Of all the pictures I looked at, there were variations of all themes. Even on the brochures it was abit of a debate (depending on what angle you viewed the stripes from)
Putting the stripes down is definately a two person job. We marked a dotted line to lay the bottom edge of the sticker along rather than try to eye in the centre of the swale line. The reflections in the duco made getting a straight edge without measurement impossible. .... And make good use of a soft rubber paddle or squegie(?) to iron out the bubbles as you go. Lay it down lightly first and then smooth it out once the bubbles are gone. I dont think removal and re-aplication is an option. Twas a nerve wracking time, especially when the wind picked up.... and we were outside.