Beefing up creatures?

[Krishnath]

Or you could use the multiheaded creature and tauric templates from Savage Species, both increase the base creatures HD as well as their CR, thus guaranteeing (sp?) higher CR creatures with more than 1 HD, other fun template to try are the (Greater) Pseudonatural and Paragon templates from the ELH as both of these templates make the creature alot harder to kill even if it just had one or two HD to begin with.

But other than templates and the elite array/max hp trick there is no way outside of increased HD/added class levels to make a creature tougher

 

[BOZ]

and the lycanthrope template is always fun as well.

 

[Krishnath]

D'oh, forgot about the lycanthropes!