I think Bungie could attract a lot more players to trials as well as make it much more rewarding with just a couple of simple changes.
Keep the current card system but offer 4 weekly pinnacle bounties like Iron Banner - these bounties could reward 2 weapons and 2 armor pieces and between 25-50 tokens but the requirements could be something of equal investment for the rewards.
Also for the love of the traveller let us keep our tokens. Removing our leftover tokens is just a terrible and deflating idea and really serves no purpose other than to restrict rewards, bungie even acknowledges a shortage of loot this season.
I think these changes would really improve trials and even people who aren't really great at pvp would have more motivation to participate and improve their skills.