what is the effective way to increase visitors to a website?

Advertise. This one is so obvious, we're going to look at it first. ...
Get Social. ...
Mix It Up. ...
Write Irresistible Headlines. ...
Pay Attention to On-Page SEO. ...
Target Long-Tail Keywords. ...
Start Guest Blogging. ...
Invite Others to Guest Blog on Your Site.

YouTube and video content marketing:
Create infographics:
USE EMAIL MARKETING-
Start A Blog:-
Integrate social media sharing everywhere:
Classified Sites:
Guest articles

Use On-Page SEO
Use Social Media Posts With Hashtags
Start Email Marketing
Set Up An Affiliate Program
Guest Post

Guest Blogging
Social Media Posts
Pay attention to On - page and off - Page SEO
Run Adwords Campaign

Write Irresistible Headlines.
Pay Attention to On-Page SEO. Target Long-Tail Keywords.

Traffic is all we need for our website, to get the traffic on your site.
Get Listed in Online Directories. ...
Build Backlinks. ...
Post to Social Media. ...
Include Hashtags in Your Posts. ...
Use Landing Pages. ...
Target Long-Tail Keywords. ...
Start Email Marketing.

To get more traffic on your site. You must promote your website on different categories off-page techniques.