Briefly said for Pirin - suitable starting places are Razlog, Bansko and Dobrinishte from the Northern side Sandanski - from the Southwest, and Melnik - from the Southern side of the mountain, Goze Delchev - from the Southeast.

From Dobrinishte you can drive to Goze Delchev hut (the road is ok) and take the cable car to Bezbog hut at 2200 m. In Bansko there's also a cable car that goes appr. a hundred meters below Todorka peak (at around 2600m) but as the ski season is over I'm not sure if it will work.

Another good starting point is the town of Sandanski, then you can drive to Yane Sandanski hut (the road is ok) and from there it is a two hour walk to Kamenitza hut at around 1700 m.

Another option is to start from Predela or Razlog up to Yavorov hut, there is a dirt road and i've no idea in what condition is it now.

Other not that popular starting points are e.g. Goze Delchev town (a good starting point for the Central and Southern parts of the mountain, which are lower and of non-alpine type) and Melnik.