This step by step walkthrough will let you take advantage of the TRIM technology for your encrypted SSD partitions for cryptsetup 1.4 or higher and kernel 3.1 or higher. This leads to a hassle-free SSD experience because
"TRIM enables the SSD to handle garbage collection overhead, that would otherwise significantly slow down future write operations to the involved blocks, in advance."
Example Setup
Notebook with SSD as the single drive, Linux installed in single ext4 LVM root partition with LVM swap partition, both over LUKS encrypted logical partition.