Keyword Research & Planning
Initial keyword research is the first step. The Google Keyword Planner offers the opportunity to understand search volumes, likely cost and competition for your chosen keywords.
Google Trends is another good tool which enables you to look at the popularity of specific keywords and compare them against others over a given period of time. It is important to also look at how competitive keywords are when planning your campaigns. If you keep things too broad, your keywords are likely to be more expensive and less effective. This is particularly problematic if you are competing in a crowded field or are a small fish in a big pond as you will always struggle to compete.
An understanding of long-tail keywords and how they can work for you is helpful here. Generally, longer tail searches are lower volume but more targeted. You are generally speaking better off targeting more lower volume keywords than fewer higher volume keywords in terms of the return on your advertising spend. For more information on keywords see our blog ‘Keyword research and why it’s important’ and ‘What are long-tail keywords and why should you be focussing on them’
Budget
If your chosen keywords are in a very competitive field, they will be expensive, this could eat through a modest budget fairly quickly.
Thinking about being more specific or about longer tail keywords will help. Limiting the time of day your adverts are seen is another way of making your budget go further. For instance, if you can identify the times when your customers are most active online and restrict your adverts to those times, your budget will go further. Similarly, restricting by geographic location may be appropriate to your business. Looking at different bidding strategies is another.