A lovely round-up of handmade Valentine Cards I found on etsy. So if you aren't into making your own, or don't have time, you can still give (and support!) handmade.
Also, for some freebies, check out my Valentine Board on Pinterest for some links to printable Valentine Cards and coupons.
Je T'aime Letterpress Card by ParrottDesignStudio
Valentine Card - Tiny Envelopes by LemonDropPapers
Happy Valentine's Day Card by k8cards
Nickname Valentine Card by evajuliet
Be My Valentine Card by AshleyPahl
I Love You Valentine Card by RowHouse14
You Are My Cup of Tea by TheWallaroo