On our monitors we always watch at least 10-20 stocks from each of these sectors:
Oils and Natural Gas, Coal, Precious Metals, Metals, Miners, Ag-Chem, Financials, Chinese momo, and Tech leaders. We also have small watch-lists on home builders, solars, REITS, Trannies, and semis. For charts we have 1 min, 3 min, 5 min, 15 min, 30 min, 60 min, and daily on each stock we highlight. The only indicators we use are 20,50,200 SMA on daily and 20 EMA on intraday along with P, S1 and R1.
For futures we watch the E-minis, crude, natural gas, copper, and gold and of course we always have an eye on the USD.
If you don't want to (or have the option of) watching 300 stocks then you can take a short-cut and watch the following ETFs:
DIA FCG FXI GDX GLD IYR IYT JJC KBE KOL MOO OIH QQQQ SLV SLX SMH SPY UNG USO UUP XHB XLE XLF XME
Even if you don't want to watch multiple stocks from each sector it's always good to have key stocks on your watch-list to give you an immediate feel for what the market is doing.
All our sectors are in separate portfolios but we have one small leader watch-list which includes the following key stocks:
NOV EOG OXY for energy
MOS AGU POT CF for ag-chem
BTU ANR MEE ACI for coal
GOOG AAPL AMZN VMW CREE for tech
GS JPM for financials
BUCY CAT JOYG for farm/construction machinery
GMCR ISRG for misc leaders
RGLD IAG BVN SSRI PAAS for gold and silver
AKS X MTL for steel
PCU FCX for copper
There are two basic steps that need to be taken before one trades successfully. One is doing your homework the night before and identifying key support and resistance areas. Two is being able to read the price-action (which includes breadth, volume, etc) and especially to be able to note divergences (for example relative weakness in banks).