The BBC had a nice little breakdown of key areas within each parties manifesto and produced it in a sort of comparing view.
BBC manifesto guide
The best way would probably to look at the key areas of the manifesto for each party and research them areas for your own views, then attempt to align your own views with the views of a party. For example, I firmly believe sticking in the EU is the right choice to ensure growth and sturdy foundations to build after the economic hardships, therefore I wouldn't vote for a party that wanted or would align themselves to the possibility of an EU in/out referendum.
That pretty much made Labour my party to vote for as any other vote for smaller parties would've been a wasted vote in my opinion.