Check what keywords your competitors are advertising on and copy them.

I don't think keywords alone will b a reason for conversions. There are many variables that come into play for conversions. I agree that Keywords let's your ad gets exposed, but from there on ... Your Ad Copy that could lead to a Click, then Your Page Content that could lead them to a Conversion.

The best way to do this could be ... run the campaign, observe what's working vs what's not & tweak as necessary.

Just my 2 cents ...

To expand on what Laksh said, keywords by themselves are not high converting. Keywords are there to target your prospects. You can use keywords wrong and if you do, they are going to be lower or not converting. For instance, if a dentist bids on "teeth", that is very general and would trigger ads for all sorts of queries containing the word teeth and therefore there would be few clicks (driving up your costs) and of those clicks, few would convert if any. He need to bid on "teeth cleaning" or "teeth removal" and other related, specific keywords. Only keywords that relate to what you do and what the searcher is looking for will convert at higher rates.

But it's not just the keywords. Your ads need to be attractive. There's less incentive to click an ad that simply says a dentist will clean your teeth versus one that also offers a relaxing atmosphere while he's doing it.

Finally, there's your landing page. If that click lands you on a page about dentures and makes you search for teeth cleaning (assuming that service is even offered), will make that traffic quickly leave. This results in no conversions of course and a waste of ad spend.

A well-organized PPC campaign will include a number of different types of keywords with different levels of intent, such as:

Brand keywords: These are keywords that include your own brand name. Brand keywords are a no-brainer; they tend to have very low costs and very high Quality Scores. In addition, they yield excellent results in terms of click-through rate (CTR) and conversion rate.

Commercial keywords: Commercial keywords are the most valuable terms in your PPC arsenal. These high-intent terms are generally used by prospects who are closest to the "bottom of the funnel" and most likely to buy.
Broader, low-intent keywords: In order to expand your account and your business's reach, it's important to also bid on some broader PPC keywords that have low intent, but help you increase brand awareness. You can increase your conversion rate on broad keywords through re marketing strategies.

Long-tail keywords: Long-tail keywords are the longer, highly specific, unique phrases that are often very low-cost and have less keyword competition. However, long-tail keywords often have low volume and limited impressions too.
Competitive keywords: It's a good idea to allocate some budget toward competitive keywords. This allows you to get your brand and offerings in front of people who are searching for your competitors' products or services.

Researching competitors keyword, is one of the best method to find highest converting keywords.

You asked the wrong question.

I have managed over thousands of campaigns and even in the same niche, the converting keywords for one site will never work as well for another site.

That's because different products have different USP.

Focus on the elements that matter.

1. Your audience
2. Your message
3. Your product

There is no specific way to get highly converting keywords. Also keywords does not convert itself. There are a lot of things that you will need any traffic driven by a specific keyword to be converted. When somebody comes using a specific keyword, they must want to get a solution. So, if you've the right solution against that keyword on your landing page with a very good description, your conversion rate will be higher. But, if you're at a starting position & dont have any knowledge of the keywords that you should target, then use Spyfu to spy the keywords of your competitors. Then use tracker to track the good converting keywords & remove the useless keywords that is wasting your money. Actually a lot of parameters will need you to work with in order to make your campaign winning with the suitable keywords.

Thanks!

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