The most important thing, and what makes a good carry, is that you know how baby should be positioned in the wrap and adjust it accordingly - whether you're wearing him in a woven or knit wrap, in a Kangaroo Carry, an Off-Center Front Carry, a Vertical / Seated Cradle Carry, a Front Double Hammock...
JPMBB tutorials videos will give you information and tips for a respectful, flexible babywearing.
Kangaroo Carry needs you to hold baby with one hand while you tie the wrap, but it gives you the possibility to evenly adjust the tension from rail to rail.
Kangaroo Carries cannot be done with the JPMBB wrap, but Front Double Hammock can be adjusted in just the same way.
You can also wear your baby in a Front Carry, Double Hammock style (front PWCC). Although it's not as precise, it's an interesting carry depending on baby's age.
Pre-tying Advanced PWCC makes front carries easy - you can put baby in a Vertical / Seated Cradle or Off-Center Front Carry, or even nurse without having to adjust Advanced PWCC.
Off-Center Front Carry is another natural position for the baby, whose head come and lies against wrapper's shoulder, just as if he were carried on his arm.
Front Double Hammock, which allows a rail to rail adjustment. (JPMBB short wrap)