Hello Sarrah,
Does the landing page have a marketo form on it, or any custom javascript? If so, you want to make sure that it's all tested propoerly. I would just make sure if it's a template that they are creating that it has the 'mkt_editable' tags. This isn't necessarily a Marketo thing, but overall make sure it's tested accross all browser platforms and machines (a tool like Litmus cand do this) because older versions of Internet Explorer doesn't support the new Marketo Forms 2.0, so that is something to consider. If your audience uses a lot of older machines you may want to use forms 1.0.