Let's see... I was in the same boat as you, I had to cover EVERYTHING up, most of the time.

Eyedrops are a must. I use Visine, you can experiment with other brands if you so choose.

Always wash your hands after smoking. Most of the smell originates from your hands, since they were handling the smoking implements.

As for the smell on your clothes, you have a few options available. As a girl, perfume would seem like an obvious choice to me. Febreeze is better suited for ridding the smell in an area (I use it in my basement if I must). I've also found using dryer sheets (The kind where the powder comes off easily) will eliminate the smell COMPLETELY, and makes your clothes smell like fresh laundry. However, it can at times leave amounts of powder visible on your clothes, but this can be rubbed off mostly.

If you're worried about breath (maybe with your boyfriend this might be an issue, breath normally isn't noticeable to most) gum always works. Mouthwash works but I've found it suspicious if you use it any time other than at night.

I forgot, you can also change your clothing, although this used excessively is suspicious (at least for us guys). As mentioned, hoodies are good to smoke in and take off afterwards, I find pants don't smell too bad after smoking, unless you're hotboxing.

A "Toobie" or "Doob Tube" (as others have stated above) works pretty well, just don't use it alone, right before someone comes home and hope they won't notice.

As for what to say if people say anything about you acting funny, I find I'm generally straight enough to pull off "I have a headache" or "I'm tired" if it's at night.

Remember, joints and especially blunts are smellier than bowls (and bongs if you stop most of the smoke from leaking) so keep this in mind. I've found smoking a bowl outside will leave almost no smell on me whatsoever, just mostly on my hands.

If you have a bathroom fan that sucks the air out, you can smoke in the bathroom as long as you manage to get all the smoke instantly sucked through the fan. Contrary to what some will say, merely taking a shower after/during smoking will not eliminate the smell effectively alone.