"Until the end of investigation phase" while this is drawn in Upkeep Phase means the 2 boosted skills and 2 reduced skills could be tested in Mythos Phase, before you can start using boosted skills in Investigation Phase.

Background: I played Making Preparations in a Stella Clarke deck with emphasis on Dilemmas and Katja Eastbank. We played a two-player campaign of Path to Carcosa and Stella joined the campaign after the Asylum. My partner played Joe Diamond.

Drawn during the investigation phase, Making Preparations provided a welcome boost to when investigating locations with high shroud and / when handling enemies. When drawn in the upkeep phase, Making Preparations was generally used to boost and one of the stats we deemed most useful for our next turn.

In almost every situation Making Preparations provided a welcome boost to two of our stats while the drawback seemed neglectable. In my opinion, the card is particularly good in decks with solid card draw. Here, the card provides boosted stats at no action similar to a skill but for the entire investigation phase and the entire team. I suspect Making Preparations becomes less useful the more players you play with as your team will often face a more diverse set of challenges which require more than two skills to solve effectively.