Reduce amount of tokens that you spend on auctions. Avoid token wars! Do not buy scouts or through negotiations. Buy when market is less active, usually early in the morning.
If you plan to sell player who is near next star, improve his quallity until you reach "negotiation" quallity = (one skill point less than next star). This way you will put your player on negotiations list where you could get offers from other players. Players which are attractive on this list are young ones, players with special ability, 2-3 positions or ones with prefered skills (like ST who has much stronger attack than defensive skill).
If you play TE on phone, downloading and installing other apps might help as well. Token rewards varies from country to country. For example, USA or Germany have "Earn Tokens" option (to watch some commercial after you get tokens). That feature isn't available in all countries.