Preparation is a big part of a successful dye attempt. Have ALL your supplies handy, and think through the process, visualize it, before you begin. Know where you are going to start and where you are going to end your project ie: start in the kitchen near the stove for super hot water to properly dissolve the dye grains for your dye bath, then end at the washing machine. Next, are you going to go with a bucket for smaller jobs, the washing machine, or a tub for larger jobs? Take the time to think it through start to finish. You will be glad you took the time upfront to properly prepare and/or decide on your course of action.
When I started my dye project, I knew the color I wanted, the big question was, How do I get there? Purple was not one of the dye powder colors available the day I was shopping, so I knew I was going to have to mix it. The "Rit" brand is the tried and true standard, and powder is probably more desirable as it seems to be able to get a deeper, darker color dye than the liquid. However, the day I was shopping, there was no red powder dye either, so I went with the liquid version.
Several key factors for me: 1) Start soaking your fabric in hot water, or washing it is best, while you are setting up your supplies, for at least 20-30mins. 2) Boiling water is best for the first step of the dye bath to completely dissolve the dye powders. You will not be putting your hands in it at this stage, and maybe not at all, if you are really careful. I used a long wooden spoon for most of my project, and only touched the fabric once taking it from the tub to the washing machine at the end. 3) Set enough time aside for the entire project - give yourself 60 to 90mins from start to finish. 4) Always use 2-3 times more dye powder or dye liquid for best results. 5) Dyeing works best on Natural Fabrics ie: cottons, linens, and silks. 6) Determine where you are going to process your dye job. 7) Do not forget to add the salt or vinegar to the dye solution!