I agree with not using straps or belts and have never used them but one thing I've found that on cycle my skin is a lot oilier and have a hard time hanging onto the bar for shrugs and deadlifts past about 3 plates. I've never really lifted that heavy but prior to using gear had no problem hanging onto the bar up to my max, which was only 365. Somewhat related, I found that using a hook grip for deadlifting was hard to get used to at first but really helped with the grip - if you could deal with the calluses halfway up your thumb ;-)
you will definately improve your grip over time just work on it. i used to have trouble with my grip as well but i continued to work on it.. keep in mind I have VERY SMALL hands, medittarean genetics so gripping 3 plate deadlifts i tend to slip out, but i have worked on it the past couple years and its getting better and better.. and i find myself outlifting dudes who weigh 50+ pounds more than me for reps