ASM Diskgroups and Underlying Mount Points

We are in the process of installing a new server that will run Grid 11.2 and Database 11.2 with ASM to manage RAW SAN mount points. We will be creating 2 databases, one needing 900G of space, one needing 600Gb of space initially. We will need to extend these at a later date with growth.

When allocating the RAW mount points, do I want to create five 300Gb mounts and then create my disk groups in ASM to consist of 3 and 2 (and later grow in 300Gb chunks), or do I want to create a 900Gb mount and a 600Gb mount and then later add on smaller mounts as they grow?