To achieve best results, you must control a number of variables. It is an excellent practice to understand the nature of such variables. This will reduce the need for repeated trials.

Superior quality materials 

To stop inks from bleeding, it is important you use premium quality inkjet paper. Bad quality inkjet papers will not hold inks as good as the premium ones. Inks bleed in such cases. Blacks will not remain much blackish after first wash. It is to be kept in mind that the printer you bought may not be ideal for the printing process you use. Use only those inks which are made for the kind of printing you do. To know which printing ink to buy, read the manufacturer instructions. The resolution of the image must not exceed 200 DPI. 

To minimize loss, make a single shirt and wash it alone. Do not print a large number of shirts at one print run in the initial stage. If you do, and if there is any mistake, you will be forced to spend a huge amount of money and lose a substantial sum. Trialling a single shirt at one time means you can take corrective action prior to committing large sums of money to a big print run order. Following the instructions mean getting excellent results. 

Saving money 

To print on a T-shirt, use the polyester or cotton blend shirts. It is preferable to use 50/590 polyester and cotton or 100 percent cotton. The print results will be identical. Do understand that a full cotton fabric tend to fray quickly during wash. A cotton-polyester blend is much more durable when it comes to transfer printing technology. The ink bonds much better to fibers. For best results, the pressing time should be increased. Doing this will allow the inks and transfer coating to penetrate much deeper into fabric fibers. Optimum time in such cases comes from a minimum of 15 seconds to 30 seconds at about 350F to 360F. The setting for the printer should be set to only plain paper. Matte coated or photo paper settings will lead to more amounts of ink to pour. This may result in inks to bleed. 

It is vital that image resolution should be limited. The Dots Per Inch or DPI of the image controls the ink amount the printer will print to transfer. The printing of images on the textiles like T-shirts or caps having resolutions greater than the 200 DPI will not appear better in higher resolutions.