maybe too simple, but...
Well, the first thing I'm going to suggest is eliminate as much reflection in your recording space as possible if you need to increase the volume and use post recording effects. Try putting some heavy blankets or carpeting on the walls in a corner, and face into it when recording,w/ mic between you and the corner, then hang one across behind you (no need to close it up though). Secondly, download a compressor. This will help
balance your performance and bring the volume as hot as can be without to much distortion. Third, Download a reverb. This will add the spacial effect to match (as close as possible) the background recording... Finally, try adjusting the mids (if using a graphic eq, 500 - 1200 htz) in the backgrounds... They often can work like a presence control. Turn it up and it will come screaming to the forefront of your recording as the mids are where our ears work the best... Turn it down a little bit, and it will seem to fade back some. Use this last trick sparingly, as you can really change the depth of sound with too much of a movement here. There are hundreds of techniques that will make a better recording, by throwing money at it, but when you are working on a budget, sometimes you have to think a bit differently. Most if not all the info given you has value, and in a full studio,with phenomenal gear and techs, they are the better way to go... but, in a home or guerrilla studio, the K.I.S.S system is all you have! Good Luck , BigBob