You should run trades by giving team goals such as:
Sellers: They will sell decent starting players to you for only first round picks. These teams would also look for young prospects as they would be trying to rebuild
Buyers: Teams that are trying to make the leap to contenders. They will trade young prospects to try and improve their team, and will look to trade their 1st round picks
Contenders: Teams that wont make any big trades and may just look for a better backup point gaurd.
Also, make a trade block along with the trade finder that shows players teams are trying to trade along with the type of player the team is looking for (Starting PF, 6th Man PG, Role Player SF)
Along with that, have an "interest" bar like players have during contract negotiation.