A  tender smile is one way to make visual contact.

Holding the eye contact a little longer  increases the message.

  Sometimes just saying  something    kind works.

Sometimes,  I just say;  "I love you."   or  I say;   "I care about you."

There are a lot of ways to express it. All of them are differents but there are a few things in common in the way which I express my love and care to them. The first one is showing to people how important they are in my life and how  do I do that? Giving to them my precious time, it doesn't even matter what kind of communication I use to do that and I say precious time because the hour won't come back again.

The second thing is keep in touch with them. Ask about things that is happening with their lifes and tell to them about mine. Being curious about their feelings and if it's possible, I might tell them some advices

The last thing is take care of them. 

I say to my boyfriend "you little crazy bitch",but I'm not normal

I am truly pathetic with this.  I like emoticons.  Not just typical smiley faces but genuinely unique emoticons the say "I love you", or "I miss you", or "Hugging you", in he most tear jerking way.  You almost feel like tattooing a smiley face on your forehead.

I do not say "I love you" or similar things. It sounds strange to me to say that. I am not used to it. Instead I use expressions such as "I'm really looking for meeting you again.", "I have been missing you.". Also I'm more interested in what has happend to her since our last meeting/chat. When it comes to a friend, I use different expressions of course. But still it can be felt that I care about her/him. It's different with animals. I have a cat. I take care of him - feeding, cleaning stuff around him, hug him, stroke him, playing with him and respect him - allow him to do what he wants to do naturally. And it's amazing how he responds to all of that. He likes to spend his time with me. Usually when I am in my room and door is closed, he is noisy and he wants to get in. He welcomes me when I arrive home. Hi likes to sleep in my bed during the night. When I go to another room in our flat, it's only a matter time and he shows up there (of course if he is not chasing birds on the balcony at that time or sleeping well in different room:D). So just sum up. When you love someone/something, your expressions (words, body language...) follow that naturally. You do nothing, it just happens. So do not worry about that.