How to link?

I have a case where I am optimizing more than one keyword.

For example keyword1 and keyword2:

From SEO point how can I link these 2 keywords?

1. keyword1, keyword2
2. keyword1 - keyword2
3. keyword1 | keyword2

I don't no idea

 

If keywords are not related IMO is best:
1. keyword1
2. keyword2

If keywords are related, maybe:
1. small phrase with keyword1 and keyword2
2. keyword1 - keyword2

 

for Title placement
all three format still good for SEO point

 

I would go with #2 keyword1 - keyword2 or just simply have a space between the two.

 

I would also go for the second form.

 

If you are talking about the anchor text, then using space is a good idea and u can also use a hyphen but not comma for sure.

 

i think using space is a good option for linking. i'm using this form and i think the result that i'm getting is good

 

putting them into phrase is what i'm doing, and results were fine with me..