IIRC, one of the FR books (I think PGtF) has optional rules for playing LA races at 1st level. The gist of it was that a character would have a penalty to all rolls/checks/etc., equal to its level adjustment. Each level after 1st would remove 1 from the penalty (& not give an actual HD level), until the character leveled to the point where the character would be normally.
For example, a drow elf (+2 LA) could start at 1st level (with one HD in any class, as normal), but would have a -2 to all rolls. At 2nd level, the character wouldn't gain a HD, but instead would then only have a -1 penalty to rolls. At 3rd level, the penalty would go away, & at 4th level, the character would gain its first additional HD, & progress from there.
However, I don't remember the specifics of what exactly the above penalty applied to. Prob' attack rolls, saves, & skill/ability checks, but not sure about ability scores, caster level, etc.