Installing patch advice on 9.1

I'm about to embark on applying my first patch upgrade since we upgraded from Infra8 to VSM9.1.2 a few weeks ago.  I'm planning on applying patch 9.1.5.

Does anyone have any advice they can give me before I start testing; is there anything new to check for when applying a patch in 9.1 to what used to happen in Infra?  Or do I basically have to check for the same things we did when upgrading in Infra?  I don't think any of the customisations I've done are out of the ordinary.

Thanks, Ian