Oh god, not again... lol
Easiest ways are to increase the amount of fermentables in the recipe... This can be as easy as more DME, or a combination of DME and sugars, or just sugars like honey, dememera, etc...
Which you use has more to do with the brew you're making than anything else.
IF you're brewing all grain, then just add more grain to the recipe and/or mash at a slightly lower temp. Mashing at a lower temp will lower the FG of the recipe, giving you more ABV with the same grain bill. Just be sure the recipe will hold up well to that. I wouldn't do that to something that's supposed to have huge mouth-feel and was originally to be mashed at 158, mashing at 152...
If you're brewing extract, or partial mashes, then just add some more DME to get closer to your ABV target. Mashing a little cooler (1-2F) should get the FG a bit lower too, so you don't need to use as much extra extract to get the result you want...
If you have a recipe in mind, post it up... Also post what your target ABV is...
I do agree with ArcaneXor too... I would rather have a smooth brew, with a decent kick but where I didn't get a hot flavor to it, than a HOT brew where it was difficult to drink... To get there, you sometimes need to age a brew, if it's a high enough ABV. Or use methods to mellow it out before it's ready for drinking...
But, taking a recipe from ~4.5% to 5.5% isn't rocket science, or a bad thing... Just be smart about it. Also realize that you'll probably want to let it go a little longer on the yeast in order to make it balanced/ready for drinking...