Commands I run on Arch Linux install

An update version where I've used plasma 5 instead of kde4 can be found here.

First Connect to the internet
Next is partitioning and mounting
After that installing
Note: in partitioning and mounting step you should have mounted the partition you want to have as root on /mnt for the following commands to be right:

# pacstrap -i /mnt base base-devel

Generate an fstab

# genfstab -U -p /mnt >> /mnt/etc/fstab 

Make sure fstab looks right

# nano /mnt/etc/fstab 

Chroot And configure the base system

# arch-chroot /mnt /bin/bash

Locale
Edit locale.gen and uncomment en_US.UTF-8 UTF-8

nano /etc/locale.gen

Generate the locale(s) specified in /etc/locale.gen:

# locale-gen

Create the /etc/locale.conf file substituting your chosen locale:

# echo LANG=en_US.UTF-8 > /etc/locale.conf

Export substituting your chosen locale:

# export LANG=en_US.UTF-8

Create a symbolic link /etc/localtime to your subzone file /usr/share/zoneinfo/Zone/SubZone using this command:

# ln -s /usr/share/zoneinfo/Zone/SubZone /etc/localtime

I use:

# ln -s /usr/share/zoneinfo/America/Belize /etc/localtime

Hardware clock
Use either UTC (recommended):

# hwclock --systohc --utc

localtime (discouraged; used by default in Windows):

# hwclock --systohc --localtime

Hostname

# echo myhostname > /etc/hostname

Add the same hostname to /etc/hosts:

# nano /etc/hosts

---------------------------------------------------
#
# /etc/hosts: static lookup table for host names
#

#<ip-address> <hostname.domain.org> <hostname>
127.0.0.1 localhost.localdomain localhost myhostname
::1  localhost.localdomain localhost

# End of file

Set the root password
Set the root password with:

# passwd

Install and configure a bootloader
I use either syslinux or grub.
See syslinux or grub for details or check the beginners guide

Users and groups Add a user. examples:

# useradd -m -G wheel -s /bin/bash archie

# useradd -m -g users -G wheel -s /bin/bash archie

Read more about users and groups here.
Display server
Install xorg-server
Display Driver
First, identify your card:

$ lspci | grep VGA

Note: if you don't get any output, try looking for a 3D controller instead:

$ lspci | grep 3D

Then install an appropriate driver. You can search the package database for a complete list of open-source video drivers:

$ pacman -Ss xf86-video

Or check this page.
You might also want to install touchpad drivers if you have laptop.

$ pacman -S xf86-input-synaptics

Installing kdebase and NetworkManager
To install kdebase and NetowrkMangager I use this command.

pacman -S kdebase kdemultimedia-kmix kdeplasma-applets-plasma-nm firefox

Enable KDM and NetworkManager with:

# systemctl enable kdm; systemctl enable NetworkManager

Exit out of chroot:

# exit

Unmount partitions:

# umount -R /mnt

Reboot:

# reboot

Useful Programs you might install

Install software:

# pacman -S exfat-utils fuse-exfat ntfs-3g kio-mtp dosfstools gparted thunderbird firefox ktorrent smplayer amarok gstreamer0.10-plugins kdesdk-kate gimp kdegraphics-okular kdegraphics-gwenview digikam blender kdenlive p7zip unrar unzip zip kdeutils-ark kdeutils-kcalc cups cups-pdf gutenprint kdeutils-print-manager system-config-printer flashplugin networkmanager-openvpn openssh libreoffice hunspell hunspell-en k3b cdrdao dvd+rw-tools oxygen-gtk3 oxygen-gtk2 kde-gtk-config wget ntp firefox-adblock-plus

Cups and ssh you need to enable yet with:

# systemctl enable org.cups.cupsd; systemctl enable sshd

Then reboot or run the following command for it to work:

# systemctl start cups; systemctl start sshd

You might want to install additional printer drivers:

pacman -S gutenprint foomatic-db foomatic-db-engine foomatic-db-nonfree hplip splix foo2zjs

Speed Up applications startup in kde
User Rob wrote on his blog this "magic trick" to improve application start-up time by 50-150ms. To enable it, create this folder in your home:

$ mkdir -p ~/.compose-cache/

Install extra fonts

pacman -S ttf-bitstream-vera ttf-dejavu ttf-freefont ttf-linux-libertine ttf-oxygen ttf-droid ttf-liberation ttf-ubuntu-font-family