Amazing trail for Milna to Hvar but if you are ready for that I would recommend much longer trail starting from Stari Grad (or Hvar if you want of course). First do avoid summer months as it is too hot and do it in spring or autumn preferably. I did it in June and it was windy day but I spent a lot of water and it was now easy.
Start from Maslinica bay near ferry port. Trail is marked well and you will be following amazing old French road called Napoleon (all of them are called like that and in relatively short period Dalmatia was under French occupation they built a lot of roads unlike Venice which did not need it).
First you start in the sparse forest and then you will be surrounded with abandoned lavender fields almost until the peak. It is very easy to walk and views are outstanding.
At the top you cross old road and there is nice chapel and konoba Vidikovac I would recommend. Then you go down to Velo Grablje with olive orchards around and after another canyon you reach very interesting abandoned Malo Grablje where only few houses are renovated.
Then you follow old mountain road and reach Milna where you go toward Hvar and there are in fact 2 trails with faster going directly to Hvar and more beautiful going along the coast.
You will go over sharp stones so take some hard shoes.
And after amazing views of turquoise sea you reach beach Pokonji dol where there is road to Hvar also following coast.
I did returned bay bus to Stari Grad but when day is long it can be done i both ways if your start early in the morning.
I have started at 8 and with average speed and lots of breaks I have reached Hvar city at around 15 hours.