The 'meta tag' keywords is depreciated, as are most of them. Best bet though is to use the 'title tag' in your 'head' section, make each one different for each page. Try to use the 'selected keyword or keyword phrase' in the 'title tag'.

Use the 'meta tag' description as well. Two sentences or so, again using a variation of your keyword or keyword phrase. Do NOT use exactly what you use in your 'title tag' either.

The 'meta tag' keyword should not be stuffed. Use only those 'relevant' keywords that actually appear on the page itself. Using other words won't help. Keep the list short to the one or two you are targetting.

The 'selected keywords/keyword phrase' should also be actually in the 'body' of your page. This should include a 'variation' in an H1 tag as well. Keep your 'h1, h2, h3' tags in order. Don't toss an h3 tag first off, but let it work in a natural progression through the 'body text'. Use CSS (Cascading Style Sheets) to set color, font sizes, etc, rather than inline codes.

If using a ton of images, try to add TEXT because that is what the SE read. Use the 'alt' tag on the image code but again, make them relevant and not for keyword stuffing.

(just a quick synopsis, cuz there is a lot more to it.)

HTH
Ian