3) Not Having a Landing Page on your Blog
Not having a dedicated landing page will be a big mistake you should not make. You need a landing page for your lead magnet. The advantage of having a dedicated landing page is the removal of distractions. There are no menus, related content or any form of distraction. Your audience is focused on one single objective which is your free offer or lead magnet.
Not using a dedicated landing page will not help you generate relevant results.
4) Not using Pop-ups
I agree with you that pop-ups could be annoying, so you may be thinking of not using them. But it has been proven to generate for much more sign-ups than the sidebar. They are an easy way to get the attention of interested readers and pass them into your funnel.
See it as a means to place your opt-in in the face of your readers. It may not sound polite, but the objective is just one thing. And that thing is to get your readers to sign up to your email list. Using an optimized and properly targeted opt=in form will work like magic.
To be subtle and polite instead of displaying your option in the middle of your content, you can allow it to pop-up when your visitor is about to use the exit button or any other form of exit.
5) Requesting Too much Personal Information
Asking for too much information could be wearisome, and you may lose your audience attention. There is no need for collecting first name, phone number, last name etc. The essential information is the first name and email address.
Other information could be highly unnecessary; an exception is where you offer essential services where these details are needed. Then it will not be a burden to your client, else requesting for excessive personal details will amount to a reduction in your opt-in rate.