What is advisable and do-able depends on many things
• STARTING POINT - many Cyclades charters start in Naxos or Paros... good choices because these have the most options reachable in 7 nights. Realize that Santorini -- since it is the farthest South, and has the most isolated & hard-to-reach Anchorage (the southern beach), will limit your choice of island.
• EXAMPLES - t may be useful to look at the itineraries offered by small-boat Sailing cruises like this: http://www.odysseysailing.gr/cruises/economy-cabin-cruise-schedule-2016.pdf
• TIMING: For best advice PLEASE give key info = WHEN? ... Aegean is VERY affected by Winds, which can play havoc w. itinerary -- you must skip places u counted on. May-June is calmest, Aug-early Sept windiest. Also, when windiest, beware of long stretches of open sea (such as between Central Cyclades and Western islands).
• ISLAND FEATURES - I haven't done small-boat thing, but have visited all the islands in Central & Western Cyclades ... and in the course of 12 GReece trips have sat in portside cafes in most, watching small-boat sailors come ashore at noon or near sunset. Some (admittedly personal) observations • NAXOS - VERY worthwhile stop: fascinating port town, wonderful beaches either adjacent to port or easy to reach via bus, many good authentic tavernas. PAROS - Ditto. ANTIPAROS - The plus of good snorkeling, total walkability. IOS - Fine beaches, not so much "Village" thing, in High Season can be like a Frat Party MYKONOS - VERY expensive; in my experience, the beaches were super-windy even late May. FOLEGANDROS - a good 1-night stop... the "high town" Chora is GORGEOUS, the main higlight of island. AMORGOS - 2 towns, I found Aegali charming & good beach, Katapola not. Famous Church at foot of Cliff and the high CHORA town are 2 chief highlights. SERIFOS - small, overlooked... port beach is mediocre, but Just around the bend is FAB beach (Livadakia); High town CHORA is main highlight. MILOS - Fascinating Volcanic Isle, Great Anchorage at Port town (but the beach there is N.G. -- there are 22 lovely beaches, but not the Port); hillside ruins & catacombs, and Stunning high town PLAKA.
SIFNOS - West-facing Port, good anchorage -but very busy-busy; best beaches elsewhere. Some of its loveliest vistas are up in hill towns but probably not feasible w. a quickie 1-night stop.
FINALLY -- The Aegean is most beautiful WATER in world, but don't expect spectacular diving/snorkeling - no coral, not the large schools of colorful fish you've ssen in Pacific & Caribbean .. in some place just rocks & grasses.
