You should. It is easy to do. The recommended keyword amount is
One keyword per 100 words.
Another thing is this Let us make baseball the keyword
Baseball: 1 time per 100 words.
Now longtail or secondary keywords: baseball hat, personalized baseball hats,
You should not use those more than one each, and really no more than 3-4 in your entire article of 350-400 words.
A way to avoid keyword stuffing is this.
Baseball fans love to wear the team baseball hat. This is typical. But replace it with this:
Baseball fans love to were hats with the favorite log of their team.
Another way to use secondary keywords without keyword stuffing.
Personalized hats can relate to a favorite sports team, cartoon character, movie star, rock star or with a special photo.