How a particular dasa is going to be is a most asked about question to astrologers. There are many techniques/pointers and strengths,placement of the dasa lord, Dasa Pravesha chakra and other pointers which have to be checked to determine how a Maha dasa is going to be for a particular native.
I believe a simple Ashtakavarga technique throws light on how a dasa is going to be.Though this has to be even more widely tested, i feel the Bhinnashtaka varga strength of the Maha dasa lord in various bhavas from Tanu Bhava to the Vyaya Bhava may give a clue as to how that bhava significations would benefit or suffer during the period of that Maha dasa. This also applies to the antardasa lord.
See the Bhinnashtakavarga strength of the Maha dasa lord in a particular house/Bhava. If the strength of the Dasa lord is more than 4 in that Bhava, significations of that bhava will be positive throughout that dasa.If it is not the case then the significations of that bhava suffer. Like wise Antardasa lord too.
If both the Dasa lord and Antardasa lord have more than 4 BAV points in a particular bhava, then that bhava will sure get a boost in that Dasa-Antardasa.
This may be applied to Divisional charts too.