To start with, you'll need the mklpp package from Bull. You can find the tool here. A mirror you can find here. Install this package via the smitty interface:

chmod +x bull.mklpp-1.2.9.0.exe
./bull.mklpp-1.2.9.0.exe
inutoc .
smitty install_all

Make a lv volume lvlpp and make a filesystems on it. Mount this filesystem under /lppdir.
Create following directory's under /lppdir: bff, in, lpp, out, and build:

cd /lppdir
mkdir bff in lpp out build

Example package build: zlib

First we create the build env:

mkdir /lppdir/lpp/zlib
mkdir /lppdir/build/zlib

Download the source of zlib and place it in /lppdir/build/zlib

cd /lppdir/build/zlib
wget http://www.zlib.net/zlib-1.2.2.tar.gz (can change)
gunzip zlib-1.2.2.tar.gz
tar -xvf zlib-1.2.2.tar
ln -s zlib-1.2.2 zlib

Be sure to change the umask to 022, so your install directory is ok. (umask 022)
Adapt the path and add /usr/local/bin to it. (export PATH=$PATH:/usr/local/bin)

Run the compille instructions for zlib:

cd /lppdir/build/zlib/zlib
./configure
make

Install zlib in a changed root env:

make install prefix=/lppdir/lpp/zlib/usr/local

Make the lpp subdirs for the package

mkdir /lppdir/lpp/zlib/usr/lpp

Pick a name for your package, take for exmaple: freeware.zlib
Make the lpp subdir for your package:

mkdir /lppdir/lpp/zlib/usr/lpp/freeware.zlib

Go into the directory /lppdir/lpp/zlib and create the lpp_name file:

4 R I freeware.zlib {
freeware.zlib.rte 1.2.1.1 01 N U en_US Zlib, Data compression library
[
*prereq bos.net.tcp.client v=4 r>1
%
INSTWORK 70 70
%
%
%
%
]
}

You will have to place the version in there(1.2.1.1) the name of the package (freeware.zlib / freeware.zlib.rte) and an explanation (Zlib, Data compression library). If needed, you can place prereq's. All other fields will be auto generated.

Make the .info subdir and create the copyright file:

mkdir /lppdir/lpp/zlib/.info
touch /lppdir/lpp/zlib/.info/freeware.zlib.rte.copyright (you can add whatever you want in this file)

Now you can build your package by doing:

cd /lppdir/lpp/zlib
mklpp

[root@sys /lppdir/lpp/zlib] mklpp
        rm -f .info/freeware.zlib.rte.al
        rm -f .info/freeware.zlib.rte.size
        rm -f .info/freeware.zlib.rte.inventory
        rm -f .info/backup_files
        rm -f usr/lpp/freeware.zlib/liblpp.a
        rm -f usr/lpp/freeware.zlib/inst_root/liblpp.a
        rm -f .info/liblpp.a
        rm -f //lppdir/out/zlib-1.2.1.1.bff //lppdir/out/zlib-1.2.1.1.bff.asc  \
		//lppdir/zip/zlib-1.2.1.1.exe //lppdir/bff/zlib-1.2.1.1.bff    \
		//lppdir/bff/zlib-1.2.1.1.bff.asc
No freeware.zlib.rte.al, applying logic to the problem...
No size file, try this for size...
No inventory file, inventing it...
No cfgfiles script, no pre-configured option, forget it
Making .info/liblpp.a archive
No root part to make
Making list of files to backup
Updating lpp_name
Making installp format distribution on //lppdir/out/zlib-1.2.1.1.bff
Target "all" is up to date.
[root@sys /lppdir/lpp/zlib]

Do note that mklpp automaticly create post and pre scripts for install and de-install in the .info/. You can add extra commands in these scripts for your own purpose.