Hot (and cold) break is the coagulation of proteins in the wort. Some of what you may be seeing can be caused by differing protein levels in your base malts. Some malts, such as continental pilsner malts traditionally have a higher percentage of proteins and therefore contribute to a much more evident hot break. In general, having a large amount of hot break is good, as it means that proteins which are partially soluble are coming out of solution, coagulating into large flocks which will settle out post boil. In my experience, the faster you reach a good rolling boil, the larger and greater amount of hot break material you will see. Most of the time, it will resemble egg drop soup. With a poorer hot break, achieving a strong cold break is important to remove the suspended proteins from the wort.
Equally important is the cold break after the boil. Here many of the smaller protein molecules are shocked out of solution, will coagulate, and settle out of the wort. This helps with reducing the probability of protein haze in your finished beer.
Additives to the later part of your boil, such as Irish moss or whirliflock will help to bring these smaller protein pieces together to settle out.