Being a web designer/dev. this is what I would suggest for landing/squeeze pages or how I build mine anyways.
I recommend NOT putting them on a sub-domain if at all possible. I always try to purchase a keyword rich domain rather, and then add them on as "addon" domains within your cPanel if purchasing hosting is limited.
(Since I do a lot of of web design, I am a resell for hostgator hosting, therefore I usually put them on there own hosting account.)
I create a Wordpress site but use a theme similar to OptimizePress or others, then I set the home page up to look just like a landing page. Although I make sure to optimize my on-page SEO for geo-targeted keywords by using A-I-O SEO, or Yoast plugin.
Then I would recommend adding additional pages in your footer to please the Google bot if you will. Add your contact, privacy policy, terms, sitemap, about us. Then always have the additional pages inter-link within their content as well as point out to a authority site like this one.
(Also, link to your main website as well. So for example, I am in the process of creating my websites for my real estate investing and I have a handful of keyword rich domains that will redirect to my plash pages, I have my domain names that I will use for my splash pages both selling and buying, then I will have my landing pages link to my main website also - hope that makes sense)
As far as post Panda/Penguin it's still to early to say how Google looks at Splash/Landing pages now. They too are still constantly changing the algorithm, so just offer good, unique content that will help the end user and you will find that your pages should do ok.