This is solely based on my experience with QIAmp DNA extraction kit (which works wonders):

• FFPE DNA extraction would firstly require the deparaffinization of the tissue sections which can be done by xylene or the commercially available deparaffinization solutions followed by administration of lysis buffer and heating for 1-2 h or overnight if the tissue samples have not yet been dissociated fully (although you might risk getting more fragmented DNA by doing so). This is followed by the spin method to extract DNA.
• DNA extraction from fresh blood samples is fairly easier as the reaction starts with administration of the lysis buffer followed by heating for ~10 min, which is significantly shorter than the FFPE protocol. You can either opt to extract the DNA with the spin or the vacuum method.

The rest of the protocol after heating for both sample types are quite identical. Some considerations to be taken include:

Good luck!