The possible value of every card in your hand should also be taken into account, as should the possibility of using it in a meld or run. Gaining Proficiency in Meld Construction. You csataaan improve your chances of creating powerful melds and runs, & eventually winning the game, by carefully considering and preparing your moves. It takes time & practice to become proficient at creating melds in Rummy Mars 41. It's critical that you stay alert & focused the entire time, and that you modify your plan of action in response to the cards that are played.