Yes, your own second guess is the correct one.

The hreflang in URL based, not domain base, so you have to specify it for every single URL that needs it.

First of all remember that the hreflang annotation is not necessarily needed in every page.
Said that, it really depends on your devs facilities what method to use, if in-code or using the sitemaps.

Both work fine, and what you should not do is using both at the same time, because the possibility of creating contradictory hreflang annotations increases.

Google explicitly advice to use 302 in case of redirection because of IP/User Agent detection, which is what it always says in others similar cases (i.e.: redirecting from desktop to mobile version of the site).

Actually you may think in building a Global page on Facebook. As you can read in the page I linked, with Global Pages:

Each brand's Global Pages structure will include local Pages for specific markets (single- or multi-country regions) and a default Page for all other markets. More details on this new framework:

• One global brand identity. Users from all countries will see the same Page name (translated into their local language), fan count, and People Talking About This (PTAT).
• One URL. Brands can promote a single URL in all off-Facebook campaigns, and users will be automatically directed to the best version of the Page for them.
• Global insights. Admins of the main Page will see insights for all global users in one easy-to-view dashboard.

The problem is that the requirement really are for strong global brands, as you can see in detail in this post.

Honestly, I looked a lot into the Facebook Business pages and I was not able to see an explicit link for creating a global page. So, I consider right what some experts say that you have to contact Facebook directly via email.

However, if your brand is global, but not with such a big budget so to afford a Global Brand Page, then the only solution is creating as many regional Brand pages as you need.

This is very easy. Just create a page normally, but then indicate in the creation process the region your Page targets for each regional pages.

Hi Eva,

your case is quite similar to the Belgium one described in a answer here above.

Said that I did not see anyone pointing you to some important thing that you're maybe forgetting to do.

Your site is a .com, a generic domain name. Generic domain names target the world by default, and that is why you have a lot of visit from Mexico for your Spanish version of the site.

Therefore, what I'd suggest you to do this check:

1. Go to Google Webmaster Tools;
2. Go to: Search Traffic > International Targeting
3. Click on the "Country" tab
4. Control if the site is targeting the USA. If not, target users in United States.

Doing that, you are telling Google that your site is meant for users in the United States and not in others countries, so it won't have that much visibility in regional Googles like google.com.mx.

Then, as suggested by others here, implement the hreflang annotations (read the resources linked in the other answers).

In the specific case of the home pages (yes, both: English version and Spanish version), the annotation will be these:

These hreflang are telling Google:

1. This URL must be presented to all people using Spanish in the USA;

2. This other URL must be presented to all people using English in the USA.

Hola,

I assume your blog is a wordpress.org and not a wordpress.com one.

If so, install the WPML plugin, which (copying and pasting from its website) l_ets you do SEO for each language separately. You can set SEO attributes for the homepage, internal pages and categories for each language. Translations appear in their unique URLs and you can even put different languages in completely different domains. WPML follows Google Webmasters’ specifications for multilingual sites to the letter, letting your sites rank high on local search results. Of course, WPML is fully compatible with SEO plugins._

It will create a /en/ subfolder for the language you're translating your blog to, which seems to be your preferred solution (in other cases, i.e. a WooCommerce based on WP, it may be better using the domain option WPML offers too).

With WPML you will be able to translate everything, not just your posts (template, plugins et al).

The URL structure will mirror the main language one, but translated to English. So if you have something like www.myblog.com/seo/como-hacer-link-building, the English version will be: www.myblog.com/en/seo/how-to-do-link-building.

It also automatically implement the hreflang annotations (so you don't have to think about them).

It is compatible with WordPress SEO by Yoast, so every translated page/post can be finely optimized.

Honestly, even though the answer here above are correct (apart the "English post" category one, which is not really the ideal solution), I warmly suggest you to use WPML.

You can think about presenting the "related products" or the "related recipees" or the "most popular recipees" (if you have a user rating system up, so that users of the site can upvote a recipe or another) as normally blogs do with "related posts".

I would present them below the product description and below the recipe, depending on the case.

I would not hide them behind a tab, because of that alert Tim is writing about in his comment (which, if it is really so - someone should test it - could be an interesting option for hiding content that you don't want Google to consider for ranking reasons).