The first poll will cover characters from Yu-Gi-Oh! ARC-V, while the second poll covers characters from the original Duel Monsters.

The ARC-V Poll lasts from September 1st, 2016 5:00 PM until September 7th, 2016 5:00 PM

The Yu-Gi-Oh! Duel Monsters Poll will last from October 1st, 2016 5:00 PM until October 7th, 2016 5:00 PM

Source

For the ARC-V Portion, the official Twitter is holding the poll, and it covers:

【#描き下ろしデュエリストカードプロテクターデザイン大投票】
みんなの熱い1票で次の候補から投票「1位」に選ばれたモチーフをもとに新たに描き下ろすイラストを使用して商品化！さっそく投票しよう！

— 【公式】遊戯王OCG (@YuGiOh_OCG_INFO) September 1, 2016

The choices are:
Yuya & Yuzu (Yuya & Zuzu)
Yuto & Ruri (Yuto & Lulu)
Yugo & Rin
Yuri & Serena (Yuri & Celina)