Multiclassing as a fighter.
1. If you're ever going to take a class with more than 2 skill points per level, it's usually a good idea to take it first.
2. If, on the other hand, you're going to take only classes with 2 skill points per level, it's often a good idea to go for the better starting hit points.
3. If you plan on having your primary role in the party be fighting, it's usually good to start off by doing that.
For instance:
Ftr 4/Wiz 6 and Wiz 6/Ftr 4 both get the same number of skill points. The difference is that the second character has three fewer hit points.
OTOH: Ftr 4/Rog 6 and Rog 6/Ftr 4 have a difference of two hit points but 18 skill points and the skill list that controls the distribution of their initial skill points.
On consideration 3, your character will generally select his 1st level feats and stats with an eye to what he'll be doing in the future. If your fighter/wizard starts play as a wizard with Power Attack and Cleave and a higher strength than int, he's going to be very tough to play effectively until he reaches level 2 and can start using good weapons and armor.
The upshot of it all is this:
Fighter/ Rogue, Bard, Ranger, Druid, Barbarian, or Monk? Start as the non-fighter part. You'll benefit from the extra skill points much more than one or two hit points.
Fighter/ Wizard, sorcerer, or cleric? Start as a fighter. The extra hit point won't hurt and starting out with the weapon and armor you eventually want to grow into enables you to buy/use masterwork stuff at first level without worrying about losing money when you sell it or having to adopt a radically different strategy at first level than throughout the rest of your career.
Fighter/Paladin? It depends primarily on whether you want to take Paladin the rest of the way. In that case, you have to take Paladin first. (And if you want 16 levels of paladin, you probably don't want to start multiclassing at level 17--a few feats would not make up for losing smite evil, mount, and lay on hands progression). If you're only in Paladin for a few levels, though, it comes down to which skill list you like better. What's more important, Intimidate (Ftr), or Sense Motive/Diplomacy/Knowledge: Religion/Knowledge: Nobility and Royalty (Pal)