I do my best as a DM to make the lower levels interesting, but I'm fortunate to have the majority of my group as long-time players. They prefer to earn what they get, not have levels handed to them. They are used to the slower progression of earlier versions of D&D and other game systems, so they like starting out squishy. In fact, we advance at 50% of the standard EXP progression. Another thing I did to make things a little more interesting (and speed up group play) is to run 1st level as solo adventures. This serves a couple of purposes for us. The first thing is that by starting out 1st level as solos, we effectively start our campaigns at 2nd level. I used 1st level as a kind of fast forward (like the beginning of a movie that gives you a character update and touches on the most pivotal moments in that character's life. The second interesting side effect of doing this is that the group starts a new campaign knowing very little about each other, which makes the start of the campaign more interesting. The only thing they decide at the start is the basic "type" of character they are going to run; warrior type, caster type, divine type or specialist/support/skill monkey type. This helps them get basically a balanced party. Fortunately for me, they are all good enough players that they know how to balance a party out regardless of what everyone chooses.
Another thing I do to help low level characters is to give them 1 special item right at the start. They're the heroes right? Why not start them off with a family heirloom or some strange and wondrous item they acquired by some fluke? It's usually in the form of a either a +1 weapon or armor or magic item worth 2,000 gp or less. It gives them the edge they need to get through the lower levels and even allows me a little more freedom in creating creative encounters.
While my group considers starting higher than 1st level cheating in a sense, they don't mind getting a little help through the first couple of levels.
One thing that always confuses me though is when I read of players getting bored if they have to fight the same type of creature twice or more in a campaign (gasp!) A creative DM should be able to set up 5 orc encounters in a row and make them all exciting and unique. Using interesting locations, environments, weather conditions, special circumstances, etc., it's pretty easy to keep a party entertained and on their toes fighting the same creatures more than once. We recently finished a campaign that was based on orcs, orogs and ogres banding together and starting a major war with the humans. To give a world a sense of there being orcs everywhere, they were the primary encounter for the party through the first 4-5 levels of the campaign. They never tired of hacking through a horde of orcs, especially once they became formidable enough to get creative in their orc destroying techniques. Sure, it's more work to make combats interesting by being more creative instead of just turning the pages of the monster manual, but I find it very rewarding when the party gets into an encounter with a new wrinkle that they have to account for.
