how do i decide a blog title

This may or may not help you ....

Treat it sort of like you're looking for that perfect domain name, don't decide immediately on on it.  Toss around some ideas, then see what comes to mind.

In the same way, start writing your content, but with your intent in mind of course.  You just may think up the perfect title while creating the content.

In your example above, You're asking do you write an article on

• SEO
• SMM
• Adwords.

All three are really different niches in digital marketing.  Each has a different strategy, or plan.

Just like in your second example, you're offering 3 different niches to choose from.

• handyman services / builds decks / additions
• someone who works tile / bathrooms / kitchens
• someone that builds houses / decks

So I ask you...

• So which topic do you know the most about ? 
• Which one can you provide useful practical advice people will find useful ?

You have some good ideas, all but " Tiles working expert New jersey" this just sucks...

It's not written for people.

Another perspective to look at it from - what keywords are you wanting to rank for?

The top ranking in many SERPs start with the keyword string and have a branded portion at the end.

Analyzing the SERPs and your competition will give you further insight into an optimal title. 

To decide a blog, you must know what are the trending topics and what are the topics that is mostly look from your target markets. Dont just do blogs just because you feel like you want it. Instead do a research on what is the commonly asked questions/problems that will make your blog helpful by answering their questions. Let me show you this blog as an example. Check this: https://bdvsbdirectvirtualservices.wordpress.com/2021/01/12/how-to-connect-instagram-to-hootsuite/

Usually it is better to start the question with How for a blog it actually works 

As tstolber recommended, I would search the phrase you want to rank for and analyze how the current top ranked pages are formatting their titles. After that, I would use a KW research tool like AHREFS, SEMRush, or Majestic and identify the variations of that search phrase with the most volume, and from those insights craft a unique title of your own.

Here's my guide in creating a blog title:

Make sure that your keyword (which describes your blog as a whole) is included in your title.
Always remember the KISS - Keep it short and simple.

If you already have a blog title, I suggest visiting Semrush and check whether your keywords/proposed blog title has a low competition and higher volume as this will help in driving traffic to your site.

I am sharing with you my blog and I hope this will help to give you an idea in creating your blog title:
https://ktnebrija.wixsite.com/ktsmmservices/post/10-things-to-do-during-self-quarantine

First, plan out your topic and then do keyword research on that particular topic.

Feel free to check my website to get more ideas.

https://meineideas.wordpress.com/

In Content Marketing, if you have lots of ideas and don't know what content is the best- they do groupings.

Group words that can be together and separate those that are irrelevant.

But, if your goal is for keyword ranking, you might as well do keyword research. 

https://maidencardoza.wordpress.com/

Before writing a blog, think about the niche around which you are going to frame your topic. Basically, what is your blog going to be about? Think about that, then set a goal or aim for your blog, think about your target audience and about the tone/voice of your blog. It should be simple in reading but informative and knowledgeable in nature.

First of all do proper keyword research then try to adjust all high volume keywords in title but dont do stuffing add them in such a way that they looks natural.