Thread: my favorite thread for all Central European embroidery is #8 Perle Cotton. I used the Hungarian-produced Puppets brand thread in a light apple green. Finca Presencia is another good choice for perle cotton, as is Valdani. I prefer these to other brands because it has a "softer" sheen that settles beautifully into fabric.
Fabric: I used a raw silk for my tank top. Other fabrics that would work well are cotton broadcloth with a lighter hand, as well as cotton lawn or light to medium-light-weight linens. For best results, use fabrics made of natural fibers.
Blouses to embroider: a great free pattern is the Sorbetto top from Colette Patterns (the version with the plain front). The Róza top (available in the shop) would also work great for this project, as well as the Uptown folk blouse (also by Kate & Rose Patterns, and available from Sew News Magazine).
Additional tools & supplies: lead pencil, a bright window, lightbox, or carbon paper for handwriting to transfer the designs; your favorite kind of embroidery needle (I use chenille needles); optional hoop, steam iron.